Knowledge (XXG)

Set cover problem

Source πŸ“

3092: 3003: 31: 1328:, with the universe represented by vertices on the left, the sets represented by vertices on the right, and edges representing the membership of elements to sets. The task is then to find a minimum cardinality subset of left-vertices that has a non-trivial intersection with each of the right-vertices, which is precisely the hitting set problem. 482:
is at least 1. The goal is to find a fractional set cover in which the sum of fractions is as small as possible. Note that a (usual) set cover is equivalent to a fractional set cover in which all fractions are either 0 or 1; therefore, the size of the smallest fractional cover is at most the size of
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for polynomial time approximation of set covering that chooses sets according to one rule: at each stage, choose the set that contains the largest number of uncovered elements. This method can be implemented in time linear in the sum of sizes of the input sets, using a
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is the problem of selecting a set of vertices (the dominating set) in a graph such that all other vertices are adjacent to at least one vertex in the dominating set. The Dominating set problem was shown to be NP complete through a reduction from Set
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problem, each set is assigned a positive weight (representing its cost), and the goal is to find a set cover with a smallest weight. The usual (unweighted) set cover corresponds to all sets having a weight of 1.
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Inapproximability results show that the greedy algorithm is essentially the best-possible polynomial time approximation algorithm for set cover up to lower order terms (see
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Information., Sandia National Laboratories. United States. Department of Energy. United States. Department of Energy. Office of Scientific and Technical (1999).
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problem, it is allowed to select fractions of sets, rather than entire sets. A fractional set cover is an assignment of a fraction (a number in ) to each set in
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below), under plausible complexity assumptions. A tighter analysis for the greedy algorithm shows that the approximation ratio is exactly
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is a computational problem equivalent to either listing all minimal hitting sets or listing all minimal set covers of a given set family.
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Gainer-Dewar, Andrew; Vera-Licona, Paola (2017), "The minimal hitting set generation problem: algorithms and computation",
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under the same assumptions, which essentially matches the approximation ratio achieved by the greedy algorithm.
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is described by a program identical to the one given above, except that the objective function to minimize is
426:. It is a problem "whose study has led to the development of fundamental techniques for the entire field" of 3175:
and the sets are induced by the intersection of the universe and geometric shapes (e.g., disks, rectangles).
2820: 1305: 1219:, as all the coefficients in the objective function and both sides of the constraints are non-negative. The 547: 3647: 3562: 2246:
sets, then a solution can be found in polynomial time that approximates the optimum to within a factor of
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Karpinski, Marek; Zelikovsky, Alexander (1998), "Approximating dense cases of covering problems",
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Benchmarks with Hidden Optimum Solutions for Set Covering, Set Packing and Winner Determination
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But there is a fractional set cover of size 1.5, in which a 0.5 fraction of each set is taken.
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There is a standard example on which the greedy algorithm achieves an approximation ratio of
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Proceedings of the DIMACS Workshop on Network Design: Connectivity and Facilities Location
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showed that set covering cannot be approximated in polynomial time to within a factor of
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equals the universe, the set cover problem is to identify a smallest sub-collection of
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is the size of the set to be covered. In other words, it finds a covering that may be
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STOC '97: Proceedings of the twenty-ninth annual ACM symposium on Theory of computing
909:, where each row corresponds to an element and each column corresponds to a set, and 114:
is equal to 4, as there are four subsets that comprise this collection. The union of
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STOC '14: Proceedings of the forty-sixth annual ACM symposium on Theory of computing
3677: 3592: 3968:"Non-approximability results for optimization problems on bounded degree instances" 3919: 3884: 3757: 3745: 3705: 3550: 3525: 3079:-factor approximation. Non weighted set cover can be adapted to the weighted case. 1357: 554: 3633: 3199:
is to choose a set cover with no element included in more than one covering set.
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For a more compact representation of the covering constraint, one can define an
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showed optimal inapproximability by proving that it cannot be approximated to
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Proceedings of the thirty-third annual ACM symposium on Theory of computing
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the smallest cover, but may be smaller. For example, consider the universe
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Proceedings of the 25th International Workshop on Principles of Diagnosis
3383: 1335:, a hitting set for a collection of geometrical objects is also called a 3967: 3892: 1146:
is described by a program identical to the one given above, except that
3841:"An Efficient Distributed Algorithm for Computing Minimal Hitting Sets" 3782:; Steurer, David (2013), "Analytical approach to parallel repetition", 3753: 3509: 3391: 3146:
is a special case of Set Cover when the universe is a set of points in
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A new multilayered PCP and the hardness of hypergraph vertex cover
3712:(1994), "On the hardness of approximating minimization problems", 3368:(August 1979), "A Greedy Heuristic for the Set-Covering Problem", 3186:
is to choose at most k sets to cover as many elements as possible.
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This greedy algorithm actually achieves an approximation ratio of
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This linear program belongs to the more general class of LPs for
1567:{\displaystyle H(n)=\sum _{k=1}^{n}{\frac {1}{k}}\leq \ln {n}+1} 406:, and the task is to find a set cover that uses the fewest sets. 3553:(2006), "Algorithmic construction of sets for k-restrictions", 3086: 2997: 2497:{\displaystyle {\tfrac {1}{2}}\log _{2}{n}\approx 0.72\ln {n}} 1360:
to prioritize the sets. It achieves an approximation ratio of
3951:, Journal of Computer and System Sciences, pp. 335–349, 2787:
proved it is NP-hard to approximate set cover to better than
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using some polynomial-time method of solving linear programs.
2082:, in that order, while the optimal solution consists only of 4008:
A compendium of NP optimization problems - Minimum Set Cover
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otherwise. Then, the covering constraint can be written as
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in the universe, the sum of fractions of sets that contain
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proves that set cover instances with sets of size at most
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can be non-integer, so the last constraint is replaced by
3974:, Association for Computing Machinery, pp. 453–461, 3897:, Association for Computing Machinery, pp. 595–601, 3345:(3rd ed.), MIT Press and McGraw-Hill, p. 1122, 3036:
the integer linear program for weighted set cover stated
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is the size of the universe). It has been shown that its
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in 1972. The optimization/search version of set cover is
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Hitting set is an equivalent reformulation of Set Cover.
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of the greedy algorithm essentially tight in this case.
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is a certain constant, under the weaker assumption that
2009:, each of which contains half of the elements from each 3103: 3037: 3014: 2784: 2364: 339:; the question is whether there is a set cover of size 3929:
Vertex cover might be hard to approximate to within 2βˆ’
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A tight analysis of the greedy algorithm for set cover
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respectively, as well as two additional disjoint sets
1284: 1258: 1230: 751:{\displaystyle \sum _{s\colon e\in s}x_{s}\geqslant 1} 240:{\displaystyle {\mathcal {C}}\subseteq {\mathcal {S}}} 3935: 3152: 3050: 2964: 2941: 2885: 2865: 2829: 2793: 2763: 2747:{\displaystyle {\bigl (}1-o(1){\bigr )}\cdot \ln {n}} 2697: 2669: 2646: 2623: 2589: 2572:{\displaystyle {\bigl (}1-o(1){\bigr )}\cdot \ln {n}} 2522: 2446: 2422: 2345: 2308: 2263: 2175: 2142: 2115: 2088: 2042: 2036:. On this input, the greedy algorithm takes the sets 2015: 1975: 1924: 1878: 1858: 1807: 1760: 1719: 1688: 1665: 1645: 1618: 1582: 1497: 1473: 1444: 1415: 1395: 1366: 1283: 1257: 1229: 1179: 1152: 1116: 1089: 1076:{\displaystyle \sum _{s\in {\mathcal {S}}}w_{s}x_{s}} 1032: 997: 957: 916: 894: 851: 804: 766: 709: 651: 456: 372: 345: 325: 285: 253: 219: 191: 167: 143: 3403: 2684: 3941: 3167: 3071: 2982: 2947: 2924: 2871: 2841: 2811: 2769: 2746: 2675: 2652: 2629: 2609: 2571: 2496: 2428: 2355: 2327: 2294: 2226: 2154: 2128: 2101: 2074: 2028: 2001: 1961: 1910: 1864: 1844: 1793: 1731: 1705: 1674: 1651: 1631: 1604: 1566: 1479: 1459: 1430: 1401: 1381: 1297: 1265: 1243: 1204: 1165: 1132: 1102: 1075: 1012: 982: 941: 900: 867: 835: 782: 750: 684: 466: 398: 351: 331: 311: 263: 239: 201: 177: 153: 3823:Combinatorial Optimization: Theory and Algorithms 2367:, then it becomes a (non-integer) linear program 2227:{\displaystyle \ln {n}-\ln {\ln {n}}+\Theta (1)} 685:{\displaystyle \sum _{s\in {\mathcal {S}}}x_{s}} 2879:cannot be approximated to a factor better than 399:{\displaystyle ({\mathcal {U}},{\mathcal {S}})} 312:{\displaystyle ({\mathcal {U}},{\mathcal {S}})} 2925:{\displaystyle \ln \Delta -O(\ln \ln \Delta )} 2437: 2166: 878:(every set is either in the set cover or not) 2725: 2700: 2550: 2525: 2371:. The algorithm can be described as follows: 605: 497:The smallest set cover has a size of 2, e.g. 8: 2688: 2289: 2277: 830: 818: 34:Example of an instance of set cover problem. 3282:"Fast stabbing of boxes in high dimensions" 3867:: CS1 maint: location missing publisher ( 3231: 2663:. A similar result with a higher value of 612: 598: 503: 3934: 3727: 3651: 3566: 3499: 3300: 3159: 3155: 3154: 3151: 3049: 2963: 2940: 2884: 2864: 2850: 2828: 2792: 2762: 2739: 2724: 2723: 2699: 2698: 2696: 2668: 2645: 2622: 2602: 2588: 2564: 2549: 2548: 2524: 2523: 2521: 2489: 2472: 2463: 2447: 2445: 2421: 2347: 2346: 2344: 2313: 2307: 2268: 2262: 2203: 2196: 2182: 2174: 2141: 2120: 2114: 2093: 2087: 2066: 2047: 2041: 2020: 2014: 1993: 1980: 1974: 1953: 1923: 1902: 1883: 1877: 1857: 1818: 1806: 1783: 1765: 1759: 1718: 1698: 1687: 1682:dense instances, however, there exists a 1664: 1644: 1623: 1617: 1593: 1581: 1553: 1534: 1528: 1517: 1496: 1472: 1443: 1438:times as large as the minimum one, where 1414: 1394: 1365: 1282: 1256: 1228: 1190: 1178: 1157: 1151: 1124: 1123: 1115: 1094: 1088: 1067: 1057: 1045: 1044: 1037: 1031: 996: 962: 956: 921: 915: 893: 859: 858: 850: 809: 803: 774: 773: 765: 736: 714: 708: 676: 664: 663: 656: 650: 458: 457: 455: 387: 386: 377: 376: 371: 344: 324: 300: 299: 290: 289: 284: 255: 254: 252: 231: 230: 221: 220: 218: 193: 192: 190: 169: 168: 166: 145: 144: 142: 3446: 3434: 3267: 3255: 3243: 2856: 2580: 1741: 410:The decision version of set covering is 108:= { {1, 2, 3}, {2, 4}, {3, 4}, {4, 5} }. 3224: 1308:for the minimum set cover problem. See 506: 3860: 792:(cover every element of the universe) 2390:for which the corresponding variable 1852:elements. The set system consists of 7: 3487:SIAM Journal on Discrete Mathematics 2516:(1998) improved this lower bound to 2436:refers to the size of the universe, 2363:in the integer linear program shown 96:For example, consider the universe, 2958:, thus making the approximation of 2685:Alon, Moshkovitz & Safra (2006) 2075:{\displaystyle S_{k},\ldots ,S_{1}} 1962:{\displaystyle 2,4,8,\ldots ,2^{k}} 1911:{\displaystyle S_{1},\ldots ,S_{k}} 1713:-approximation algorithm for every 1298:{\displaystyle \scriptstyle \log n} 1244:{\displaystyle \scriptstyle \log n} 1133:{\displaystyle s\in {\mathcal {S}}} 868:{\displaystyle s\in {\mathcal {S}}} 783:{\displaystyle e\in {\mathcal {U}}} 633:can be formulated as the following 3839:Cardoso, Nuno; Abreu, Rui (2014), 3465:. United States. Dept. of Energy. 3371:Mathematics of Operations Research 2971: 2916: 2892: 2866: 2242:If each element occurs in at most 2212: 2136:. An example of such an input for 1639:is the maximum cardinality set of 1320:Set covering is equivalent to the 93:whose union equals the universe. 27:Classical problem in combinatorics 25: 3462:On the Red-Blue Set Cover Problem 3134:is a special case of Hitting Set. 2823:is true, this can be improved to 1205:{\displaystyle 0\leq x_{s}\leq 1} 73:, (henceforth referred to as the 3168:{\displaystyle \mathbb {R} ^{d}} 3090: 3001: 2295:{\displaystyle x_{S}\in \{0,1\}} 836:{\displaystyle x_{s}\in \{0,1\}} 137:More formally, given a universe 3404:Karpinski & Zelikovsky 1998 3140:is a special case of Set Cover. 3066: 3054: 2919: 2901: 2720: 2714: 2610:{\displaystyle c\cdot \ln {n}} 2545: 2539: 2356:{\displaystyle {\mathcal {S}}} 2221: 2215: 1831: 1819: 1794:{\displaystyle \log _{2}(n)/2} 1780: 1774: 1605:{\displaystyle H(s^{\prime })} 1599: 1586: 1507: 1501: 1454: 1448: 1425: 1419: 1376: 1370: 1266:{\displaystyle \scriptstyle n} 950:if element e is in set s, and 696:(minimize the number of sets) 508:Covering/packing-problem pairs 467:{\displaystyle {\mathcal {S}}} 416:Karp's 21 NP-complete problems 393: 373: 306: 286: 264:{\displaystyle {\mathcal {U}}} 202:{\displaystyle {\mathcal {U}}} 178:{\displaystyle {\mathcal {S}}} 154:{\displaystyle {\mathcal {U}}} 1: 3302:10.1016/S0304-3975(98)00336-3 3280:Nielsen, Frank (2000-09-06). 2983:{\displaystyle \ln \Delta +1} 2812:{\displaystyle f-1-\epsilon } 2583:established a lower bound of 1845:{\displaystyle n=2^{(k+1)}-2} 1013:{\displaystyle Ax\geqslant 1} 495:= { {1, 2}, {2, 3}, {3, 1} }. 474:, such that for each element 3339:(2009) , "Exercise 35.3-3", 3289:Theoretical Computer Science 2438:Lund & Yannakakis (1994) 1312:for a detailed explanation. 1310:randomized rounding#setcover 2842:{\displaystyle f-\epsilon } 2328:{\displaystyle x_{S}\geq 0} 2002:{\displaystyle T_{0},T_{1}} 1801:. The universe consists of 1632:{\displaystyle s^{\prime }} 490:and the collection of sets 103:and the collection of sets 42:is a classical question in 4059: 3957:10.1016/j.jcss.2007.06.019 3617:Introduction to Algorithms 3418:. STOC'96, Pages 435-441, 3342:Introduction to Algorithms 2783:In low-frequency systems, 2689:Dinur & Steurer (2013) 2162:is pictured on the right. 625:Linear program formulation 3942:{\displaystyle \epsilon } 3764:, ACM, pp. 475–484, 3072:{\displaystyle O(\log n)} 2412:Inapproximability results 2375:Find an optimal solution 2167:Inapproximability results 983:{\displaystyle A_{e,s}=0} 942:{\displaystyle A_{e,s}=1} 4038:Approximation algorithms 3825:(5 ed.), Springer, 3798:Approximation Algorithms 3184:Maximum coverage problem 1872:pairwise disjoint sets 1706:{\displaystyle c\ln {m}} 1675:{\displaystyle \delta -} 428:approximation algorithms 3786:, ACM, pp. 624–633 3577:10.1145/1150334.1150336 2872:{\displaystyle \Delta } 2851:Khot & Regev (2008) 2821:Unique games conjecture 2683:was recently proved by 1316:Hitting set formulation 1306:approximation algorithm 560:Maximum independent set 247:of sets whose union is 3943: 3821:; Vygen, Jens (2012), 3232:Korte & Vygen 2012 3169: 3073: 2984: 2949: 2926: 2873: 2843: 2813: 2771: 2748: 2677: 2654: 2653:{\displaystyle \not =} 2631: 2611: 2581:Raz & Safra (1997) 2573: 2498: 2430: 2357: 2329: 2296: 2228: 2156: 2130: 2103: 2076: 2030: 2003: 1963: 1912: 1866: 1846: 1795: 1751: 1746:Tight example for the 1733: 1732:{\displaystyle c>0} 1707: 1676: 1653: 1633: 1606: 1568: 1533: 1481: 1461: 1432: 1403: 1383: 1333:computational geometry 1299: 1277:indeed gives a factor- 1267: 1245: 1223:of the ILP is at most 1206: 1167: 1134: 1104: 1077: 1014: 984: 943: 902: 869: 837: 784: 752: 686: 635:integer linear program 468: 400: 366:, the input is a pair 353: 333: 313: 279:, the input is a pair 265: 241: 203: 179: 155: 124:{ {1, 2, 3}, {4, 5} }‍ 35: 3980:10.1145/380752.380839 3944: 3903:10.1145/780542.780629 3881:Guruswami, Venkatesan 3729:10.1145/185675.306789 3662:10.1145/285055.285059 3605:Leiserson, Charles E. 3555:ACM Trans. Algorithms 3424:10.1145/237814.237991 3329:Leiserson, Charles E. 3170: 3074: 2985: 2950: 2927: 2874: 2844: 2814: 2772: 2749: 2678: 2655: 2632: 2612: 2574: 2510:quasi-polynomial time 2499: 2431: 2399:has value at least 1/ 2358: 2330: 2297: 2238:Low-frequency systems 2229: 2157: 2131: 2129:{\displaystyle T_{1}} 2104: 2102:{\displaystyle T_{0}} 2077: 2031: 2029:{\displaystyle S_{i}} 2004: 1964: 1913: 1867: 1847: 1796: 1745: 1734: 1708: 1677: 1654: 1634: 1607: 1569: 1513: 1482: 1462: 1433: 1404: 1384: 1300: 1268: 1246: 1207: 1168: 1166:{\displaystyle x_{s}} 1135: 1110:is the weight of set 1105: 1103:{\displaystyle w_{s}} 1078: 1015: 985: 944: 903: 870: 838: 785: 753: 687: 469: 401: 354: 334: 314: 266: 242: 204: 180: 156: 33: 4028:NP-complete problems 3933: 3856:10.5281/zenodo.10037 3384:10.1287/moor.4.3.233 3212:Monotone dualization 3150: 3083:Fractional set cover 3048: 2962: 2939: 2883: 2863: 2827: 2791: 2761: 2695: 2667: 2644: 2621: 2587: 2520: 2444: 2420: 2343: 2306: 2261: 2173: 2140: 2113: 2086: 2040: 2013: 1973: 1922: 1876: 1856: 1805: 1758: 1717: 1686: 1663: 1643: 1616: 1580: 1495: 1471: 1460:{\displaystyle H(n)} 1442: 1431:{\displaystyle H(n)} 1413: 1393: 1382:{\displaystyle H(s)} 1364: 1281: 1255: 1227: 1177: 1150: 1144:Fractional set cover 1114: 1087: 1030: 995: 955: 914: 892: 849: 802: 764: 707: 649: 555:Minimum vertex cover 454: 448:fractional set cover 370: 364:optimization problem 343: 323: 283: 251: 217: 189: 165: 141: 3804:, Springer-Verlag, 3710:Yannakakis, Mihalis 3437:, pp. 118–119) 3270:, pp. 110–112) 3206:Set-cover abduction 3202:Red-blue set cover. 3197:Exact cover problem 3144:Geometric set cover 3042:randomized rounding 2785:Dinur et al. (2003) 2155:{\displaystyle k=3} 1322:hitting set problem 536:Maximum set packing 499:{ {1, 2}, {2, 3} }. 52:operations research 4033:Linear programming 3939: 3793:Vazirani, Vijay V. 3715:Journal of the ACM 3639:Journal of the ACM 3510:10.1137/15M1055024 3165: 3102:. You can help by 3069: 3013:. You can help by 2994:Weighted set cover 2980: 2945: 2922: 2869: 2839: 2809: 2767: 2744: 2673: 2650: 2627: 2607: 2569: 2494: 2457: 2426: 2353: 2325: 2292: 2257:If the constraint 2224: 2152: 2126: 2099: 2072: 2026: 1999: 1959: 1908: 1862: 1842: 1791: 1752: 1729: 1703: 1672: 1649: 1629: 1602: 1564: 1477: 1457: 1428: 1399: 1379: 1295: 1294: 1263: 1262: 1241: 1240: 1202: 1163: 1130: 1100: 1073: 1052: 1024:Weighted set cover 1010: 980: 939: 898: 865: 833: 780: 748: 731: 682: 671: 543:Minimum edge cover 464: 440:weighted set cover 396: 349: 329: 309: 261: 237: 199: 175: 151: 36: 4043:Covering problems 3850:, Graz, Austria, 3832:978-3-642-24487-2 3811:978-3-540-65367-7 3771:978-0-89791-888-6 3626:978-0-262-03293-3 3609:Rivest, Ronald L. 3601:Cormen, Thomas H. 3333:Rivest, Ronald L. 3325:Cormen, Thomas H. 3120: 3119: 3031: 3030: 2948:{\displaystyle =} 2770:{\displaystyle =} 2676:{\displaystyle c} 2630:{\displaystyle c} 2456: 2429:{\displaystyle n} 1865:{\displaystyle k} 1652:{\displaystyle S} 1542: 1480:{\displaystyle n} 1402:{\displaystyle s} 1217:covering problems 1033: 901:{\displaystyle A} 882: 881: 710: 652: 631:set cover problem 622: 621: 589: 588: 584:Rectangle packing 531:Minimum set cover 519:Covering problems 362:In the set cover 352:{\displaystyle k} 332:{\displaystyle k} 275:In the set cover 110:In this example, 101:= {1, 2, 3, 4, 5} 56:complexity theory 40:set cover problem 16:(Redirected from 4050: 4023:Families of sets 3992: 3959: 3948: 3946: 3945: 3940: 3915: 3872: 3866: 3858: 3845: 3835: 3814: 3803: 3787: 3774: 3748: 3731: 3701: 3680: 3655: 3629: 3595: 3570: 3547:Moshkovitz, Dana 3529: 3528: 3503: 3481: 3475: 3474: 3456: 3450: 3444: 3438: 3432: 3426: 3412: 3406: 3401: 3395: 3394: 3362: 3356: 3355: 3321: 3315: 3314: 3304: 3286: 3277: 3271: 3265: 3259: 3253: 3247: 3241: 3235: 3229: 3174: 3172: 3171: 3166: 3164: 3163: 3158: 3123:Related problems 3115: 3112: 3094: 3087: 3078: 3076: 3075: 3070: 3026: 3023: 3005: 2998: 2989: 2987: 2986: 2981: 2954: 2952: 2951: 2946: 2931: 2929: 2928: 2923: 2878: 2876: 2875: 2870: 2848: 2846: 2845: 2840: 2818: 2816: 2815: 2810: 2776: 2774: 2773: 2768: 2753: 2751: 2750: 2745: 2743: 2729: 2728: 2704: 2703: 2682: 2680: 2679: 2674: 2659: 2657: 2656: 2651: 2636: 2634: 2633: 2628: 2616: 2614: 2613: 2608: 2606: 2578: 2576: 2575: 2570: 2568: 2554: 2553: 2529: 2528: 2503: 2501: 2500: 2495: 2493: 2476: 2468: 2467: 2458: 2449: 2435: 2433: 2432: 2427: 2403:in the solution 2379:for the program 2362: 2360: 2359: 2354: 2352: 2351: 2334: 2332: 2331: 2326: 2318: 2317: 2301: 2299: 2298: 2293: 2273: 2272: 2233: 2231: 2230: 2225: 2208: 2207: 2186: 2161: 2159: 2158: 2153: 2135: 2133: 2132: 2127: 2125: 2124: 2108: 2106: 2105: 2100: 2098: 2097: 2081: 2079: 2078: 2073: 2071: 2070: 2052: 2051: 2035: 2033: 2032: 2027: 2025: 2024: 2008: 2006: 2005: 2000: 1998: 1997: 1985: 1984: 1968: 1966: 1965: 1960: 1958: 1957: 1917: 1915: 1914: 1909: 1907: 1906: 1888: 1887: 1871: 1869: 1868: 1863: 1851: 1849: 1848: 1843: 1835: 1834: 1800: 1798: 1797: 1792: 1787: 1770: 1769: 1748:greedy algorithm 1738: 1736: 1735: 1730: 1712: 1710: 1709: 1704: 1702: 1681: 1679: 1678: 1673: 1658: 1656: 1655: 1650: 1638: 1636: 1635: 1630: 1628: 1627: 1611: 1609: 1608: 1603: 1598: 1597: 1573: 1571: 1570: 1565: 1557: 1543: 1535: 1532: 1527: 1486: 1484: 1483: 1478: 1466: 1464: 1463: 1458: 1437: 1435: 1434: 1429: 1408: 1406: 1405: 1400: 1388: 1386: 1385: 1380: 1353:greedy algorithm 1347:Greedy algorithm 1331:In the field of 1304: 1302: 1301: 1296: 1272: 1270: 1269: 1264: 1250: 1248: 1247: 1242: 1211: 1209: 1208: 1203: 1195: 1194: 1172: 1170: 1169: 1164: 1162: 1161: 1139: 1137: 1136: 1131: 1129: 1128: 1109: 1107: 1106: 1101: 1099: 1098: 1082: 1080: 1079: 1074: 1072: 1071: 1062: 1061: 1051: 1050: 1049: 1019: 1017: 1016: 1011: 989: 987: 986: 981: 973: 972: 948: 946: 945: 940: 932: 931: 907: 905: 904: 899: 886:incidence matrix 874: 872: 871: 866: 864: 863: 842: 840: 839: 834: 814: 813: 789: 787: 786: 781: 779: 778: 757: 755: 754: 749: 741: 740: 730: 691: 689: 688: 683: 681: 680: 670: 669: 668: 640: 639: 614: 607: 600: 579:Polygon covering 548:Maximum matching 524:Packing problems 515: 514: 504: 500: 496: 489: 473: 471: 470: 465: 463: 462: 405: 403: 402: 397: 392: 391: 382: 381: 358: 356: 355: 350: 338: 336: 335: 330: 318: 316: 315: 310: 305: 304: 295: 294: 277:decision problem 270: 268: 267: 262: 260: 259: 246: 244: 243: 238: 236: 235: 226: 225: 208: 206: 205: 200: 198: 197: 184: 182: 181: 176: 174: 173: 160: 158: 157: 152: 150: 149: 133: 129: 125: 121: 117: 113: 109: 102: 92: 84: 80: 72: 48:computer science 21: 4058: 4057: 4053: 4052: 4051: 4049: 4048: 4047: 4013: 4012: 3999: 3990: 3962: 3931: 3930: 3918: 3913: 3875: 3859: 3843: 3838: 3833: 3819:Korte, Bernhard 3817: 3812: 3801: 3791: 3778: 3772: 3752: 3704: 3699: 3684: 3632: 3627: 3613:Stein, Clifford 3599: 3568:10.1.1.138.8682 3541: 3538: 3533: 3532: 3483: 3482: 3478: 3458: 3457: 3453: 3445: 3441: 3433: 3429: 3413: 3409: 3402: 3398: 3364: 3363: 3359: 3353: 3337:Stein, Clifford 3323: 3322: 3318: 3284: 3279: 3278: 3274: 3266: 3262: 3254: 3250: 3242: 3238: 3230: 3226: 3221: 3153: 3148: 3147: 3125: 3116: 3110: 3107: 3100:needs expansion 3085: 3046: 3045: 3027: 3021: 3018: 3011:needs expansion 2996: 2960: 2959: 2937: 2936: 2881: 2880: 2861: 2860: 2857:Trevisan (2001) 2825: 2824: 2789: 2788: 2759: 2758: 2693: 2692: 2665: 2664: 2642: 2641: 2619: 2618: 2585: 2584: 2518: 2517: 2459: 2442: 2441: 2418: 2417: 2414: 2406: 2402: 2398: 2397: 2393: 2389: 2382: 2378: 2370: 2341: 2340: 2338: 2309: 2304: 2303: 2302:is replaced by 2264: 2259: 2258: 2249: 2245: 2240: 2171: 2170: 2138: 2137: 2116: 2111: 2110: 2089: 2084: 2083: 2062: 2043: 2038: 2037: 2016: 2011: 2010: 1989: 1976: 1971: 1970: 1949: 1920: 1919: 1898: 1879: 1874: 1873: 1854: 1853: 1814: 1803: 1802: 1761: 1756: 1755: 1715: 1714: 1684: 1683: 1661: 1660: 1641: 1640: 1619: 1614: 1613: 1589: 1578: 1577: 1493: 1492: 1489:harmonic number 1469: 1468: 1440: 1439: 1411: 1410: 1391: 1390: 1362: 1361: 1349: 1326:bipartite graph 1318: 1279: 1278: 1253: 1252: 1225: 1224: 1221:integrality gap 1186: 1175: 1174: 1153: 1148: 1147: 1112: 1111: 1090: 1085: 1084: 1063: 1053: 1028: 1027: 993: 992: 958: 953: 952: 917: 912: 911: 890: 889: 847: 846: 805: 800: 799: 762: 761: 732: 705: 704: 672: 647: 646: 627: 618: 498: 491: 484: 452: 451: 436: 414:. It is one of 368: 367: 341: 340: 321: 320: 319:and an integer 281: 280: 249: 248: 215: 214: 213:is a subfamily 187: 186: 163: 162: 139: 138: 131: 127: 123: 119: 115: 111: 104: 97: 90: 82: 78: 66: 28: 23: 22: 15: 12: 11: 5: 4056: 4054: 4046: 4045: 4040: 4035: 4030: 4025: 4015: 4014: 4011: 4010: 4005: 3998: 3997:External links 3995: 3994: 3993: 3988: 3964:Trevisan, Luca 3960: 3938: 3916: 3911: 3873: 3836: 3831: 3815: 3810: 3789: 3776: 3770: 3750: 3722:(5): 960–981, 3702: 3697: 3682: 3653:10.1.1.70.5014 3646:(4): 634–652, 3630: 3625: 3597: 3561:(2): 153–177, 3537: 3534: 3531: 3530: 3476: 3451: 3447:Vazirani (2001 3439: 3435:Vazirani (2001 3427: 3407: 3396: 3378:(3): 233–235, 3357: 3351: 3316: 3272: 3268:Vazirani (2001 3260: 3258:, p. 108) 3256:Vazirani (2001 3248: 3244:Vazirani (2001 3236: 3234:, p. 414. 3223: 3222: 3220: 3217: 3216: 3215: 3209: 3203: 3200: 3194: 3190:Dominating set 3187: 3181: 3176: 3162: 3157: 3141: 3135: 3129: 3124: 3121: 3118: 3117: 3111:September 2023 3097: 3095: 3084: 3081: 3068: 3065: 3062: 3059: 3056: 3053: 3040:, one may use 3029: 3028: 3008: 3006: 2995: 2992: 2979: 2976: 2973: 2970: 2967: 2944: 2921: 2918: 2915: 2912: 2909: 2906: 2903: 2900: 2897: 2894: 2891: 2888: 2868: 2838: 2835: 2832: 2808: 2805: 2802: 2799: 2796: 2766: 2742: 2738: 2735: 2732: 2727: 2722: 2719: 2716: 2713: 2710: 2707: 2702: 2672: 2649: 2626: 2605: 2601: 2598: 2595: 2592: 2567: 2563: 2560: 2557: 2552: 2547: 2544: 2541: 2538: 2535: 2532: 2527: 2492: 2488: 2485: 2482: 2479: 2475: 2471: 2466: 2462: 2455: 2452: 2425: 2413: 2410: 2409: 2408: 2404: 2400: 2395: 2394: 2391: 2387: 2386:Pick all sets 2384: 2380: 2376: 2368: 2350: 2336: 2324: 2321: 2316: 2312: 2291: 2288: 2285: 2282: 2279: 2276: 2271: 2267: 2247: 2243: 2239: 2236: 2223: 2220: 2217: 2214: 2211: 2206: 2202: 2199: 2195: 2192: 2189: 2185: 2181: 2178: 2151: 2148: 2145: 2123: 2119: 2096: 2092: 2069: 2065: 2061: 2058: 2055: 2050: 2046: 2023: 2019: 1996: 1992: 1988: 1983: 1979: 1956: 1952: 1948: 1945: 1942: 1939: 1936: 1933: 1930: 1927: 1905: 1901: 1897: 1894: 1891: 1886: 1882: 1861: 1841: 1838: 1833: 1830: 1827: 1824: 1821: 1817: 1813: 1810: 1790: 1786: 1782: 1779: 1776: 1773: 1768: 1764: 1728: 1725: 1722: 1701: 1697: 1694: 1691: 1671: 1668: 1648: 1626: 1622: 1601: 1596: 1592: 1588: 1585: 1563: 1560: 1556: 1552: 1549: 1546: 1541: 1538: 1531: 1526: 1523: 1520: 1516: 1512: 1509: 1506: 1503: 1500: 1476: 1456: 1453: 1450: 1447: 1427: 1424: 1421: 1418: 1398: 1378: 1375: 1372: 1369: 1348: 1345: 1317: 1314: 1293: 1290: 1287: 1261: 1239: 1236: 1233: 1201: 1198: 1193: 1189: 1185: 1182: 1160: 1156: 1127: 1122: 1119: 1097: 1093: 1070: 1066: 1060: 1056: 1048: 1043: 1040: 1036: 1009: 1006: 1003: 1000: 979: 976: 971: 968: 965: 961: 938: 935: 930: 927: 924: 920: 897: 880: 879: 876: 862: 857: 854: 843: 832: 829: 826: 823: 820: 817: 812: 808: 797: 794: 793: 790: 777: 772: 769: 758: 747: 744: 739: 735: 729: 726: 723: 720: 717: 713: 702: 698: 697: 694: 692: 679: 675: 667: 662: 659: 655: 644: 626: 623: 620: 619: 617: 616: 609: 602: 594: 591: 590: 587: 586: 581: 575: 574: 569: 563: 562: 557: 551: 550: 545: 539: 538: 533: 527: 526: 521: 511: 510: 461: 435: 432: 408: 407: 395: 390: 385: 380: 375: 360: 348: 328: 308: 303: 298: 293: 288: 258: 234: 229: 224: 196: 185:of subsets of 172: 148: 85:subsets whose 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 4055: 4044: 4041: 4039: 4036: 4034: 4031: 4029: 4026: 4024: 4021: 4020: 4018: 4009: 4006: 4004: 4001: 4000: 3996: 3991: 3989:1-58113-349-9 3985: 3981: 3977: 3973: 3969: 3965: 3961: 3958: 3954: 3950: 3949: 3936: 3925: 3921: 3920:Khot, Subhash 3917: 3914: 3908: 3904: 3900: 3896: 3895: 3890: 3886: 3885:Khot, Subhash 3882: 3878: 3874: 3870: 3864: 3857: 3853: 3849: 3842: 3837: 3834: 3828: 3824: 3820: 3816: 3813: 3807: 3800: 3799: 3794: 3790: 3785: 3781: 3777: 3773: 3767: 3763: 3759: 3758:Safra, Shmuel 3755: 3751: 3747: 3743: 3739: 3735: 3730: 3725: 3721: 3717: 3716: 3711: 3707: 3706:Lund, Carsten 3703: 3700: 3698:9780821870846 3694: 3690: 3689: 3683: 3679: 3675: 3671: 3667: 3663: 3659: 3654: 3649: 3645: 3641: 3640: 3635: 3631: 3628: 3622: 3618: 3614: 3610: 3606: 3602: 3598: 3594: 3590: 3586: 3582: 3578: 3574: 3569: 3564: 3560: 3556: 3552: 3551:Safra, Shmuel 3548: 3544: 3540: 3539: 3535: 3527: 3523: 3519: 3515: 3511: 3507: 3502: 3497: 3494:(1): 63–100, 3493: 3489: 3488: 3480: 3477: 3472: 3468: 3464: 3463: 3455: 3452: 3449:, Chapter 14) 3448: 3443: 3440: 3436: 3431: 3428: 3425: 3421: 3417: 3414:SlavΓ­k Petr 3411: 3408: 3405: 3400: 3397: 3393: 3389: 3385: 3381: 3377: 3373: 3372: 3367: 3361: 3358: 3354: 3352:0-262-03384-4 3348: 3344: 3343: 3338: 3334: 3330: 3326: 3320: 3317: 3312: 3308: 3303: 3298: 3294: 3290: 3283: 3276: 3273: 3269: 3264: 3261: 3257: 3252: 3249: 3246:, p. 15) 3245: 3240: 3237: 3233: 3228: 3225: 3218: 3213: 3210: 3207: 3204: 3201: 3198: 3195: 3191: 3188: 3185: 3182: 3180: 3177: 3160: 3145: 3142: 3139: 3136: 3133: 3130: 3127: 3126: 3122: 3114: 3105: 3101: 3098:This section 3096: 3093: 3089: 3088: 3082: 3080: 3063: 3060: 3057: 3051: 3043: 3039: 3035: 3025: 3022:November 2017 3016: 3012: 3009:This section 3007: 3004: 3000: 2999: 2993: 2991: 2977: 2974: 2968: 2965: 2957: 2942: 2935: 2913: 2910: 2907: 2904: 2898: 2895: 2889: 2886: 2858: 2854: 2852: 2849:as proven by 2836: 2833: 2830: 2822: 2806: 2803: 2800: 2797: 2794: 2786: 2781: 2779: 2764: 2757: 2740: 2736: 2733: 2730: 2717: 2711: 2708: 2705: 2690: 2686: 2670: 2662: 2647: 2640: 2624: 2603: 2599: 2596: 2593: 2590: 2582: 2565: 2561: 2558: 2555: 2542: 2536: 2533: 2530: 2515: 2511: 2507: 2490: 2486: 2483: 2480: 2477: 2473: 2469: 2464: 2460: 2453: 2450: 2439: 2423: 2411: 2385: 2374: 2373: 2372: 2366: 2322: 2319: 2314: 2310: 2286: 2283: 2280: 2274: 2269: 2265: 2255: 2253: 2252:LP relaxation 2237: 2235: 2218: 2209: 2204: 2200: 2197: 2193: 2190: 2187: 2183: 2179: 2176: 2168: 2163: 2149: 2146: 2143: 2121: 2117: 2094: 2090: 2067: 2063: 2059: 2056: 2053: 2048: 2044: 2021: 2017: 1994: 1990: 1986: 1981: 1977: 1954: 1950: 1946: 1943: 1940: 1937: 1934: 1931: 1928: 1925: 1903: 1899: 1895: 1892: 1889: 1884: 1880: 1859: 1839: 1836: 1828: 1825: 1822: 1815: 1811: 1808: 1788: 1784: 1777: 1771: 1766: 1762: 1749: 1744: 1740: 1726: 1723: 1720: 1699: 1695: 1692: 1689: 1669: 1666: 1646: 1620: 1590: 1583: 1574: 1561: 1558: 1554: 1550: 1547: 1544: 1539: 1536: 1529: 1524: 1521: 1518: 1514: 1510: 1504: 1498: 1490: 1474: 1451: 1445: 1422: 1416: 1396: 1373: 1367: 1359: 1354: 1346: 1344: 1342: 1338: 1334: 1329: 1327: 1323: 1315: 1313: 1311: 1307: 1291: 1288: 1285: 1276: 1259: 1237: 1234: 1231: 1222: 1218: 1213: 1199: 1196: 1191: 1187: 1183: 1180: 1158: 1154: 1145: 1141: 1120: 1117: 1095: 1091: 1068: 1064: 1058: 1054: 1041: 1038: 1034: 1025: 1021: 1007: 1004: 1001: 998: 990: 977: 974: 969: 966: 963: 959: 949: 936: 933: 928: 925: 922: 918: 908: 895: 887: 877: 855: 852: 844: 827: 824: 821: 815: 810: 806: 798: 796: 795: 791: 770: 767: 759: 745: 742: 737: 733: 727: 724: 721: 718: 715: 711: 703: 700: 699: 695: 693: 677: 673: 660: 657: 653: 645: 642: 641: 638: 636: 632: 624: 615: 610: 608: 603: 601: 596: 595: 593: 592: 585: 582: 580: 577: 576: 573: 570: 568: 565: 564: 561: 558: 556: 553: 552: 549: 546: 544: 541: 540: 537: 534: 532: 529: 528: 525: 522: 520: 517: 516: 513: 512: 509: 505: 502: 494: 487: 481: 477: 449: 444: 441: 433: 431: 429: 425: 421: 417: 413: 383: 365: 361: 346: 326: 296: 278: 274: 273: 272: 227: 212: 161:and a family 135: 107: 100: 94: 88: 81:, of a given 76: 70: 64: 59: 57: 53: 49: 45: 44:combinatorics 41: 32: 19: 3971: 3928: 3893: 3847: 3822: 3797: 3783: 3761: 3719: 3713: 3687: 3643: 3637: 3634:Feige, Uriel 3616: 3558: 3554: 3491: 3485: 3479: 3461: 3454: 3442: 3430: 3410: 3399: 3375: 3369: 3360: 3341: 3319: 3295:(1): 53–72. 3292: 3288: 3275: 3263: 3251: 3239: 3227: 3132:Vertex cover 3108: 3104:adding to it 3099: 3032: 3019: 3015:adding to it 3010: 2955: 2933: 2855: 2782: 2777: 2755: 2660: 2638: 2512:algorithms. 2505: 2415: 2256: 2241: 2164: 1753: 1575: 1358:bucket queue 1350: 1341:piercing set 1340: 1337:stabbing set 1336: 1330: 1321: 1319: 1214: 1143: 1142: 1023: 1022: 951: 910: 888: 883: 630: 628: 567:Bin covering 530: 492: 485: 479: 475: 447: 445: 439: 437: 418:shown to be 409: 210: 136: 134:has size 2. 118:is equal to 105: 98: 95: 68: 65:of elements 60: 39: 37: 3924:Regev, Oded 3889:Regev, Oded 3877:Dinur, Irit 3780:Dinur, Irit 3366:Chvatal, V. 3179:Set packing 1918:with sizes 1351:There is a 701:subject to 572:Bin packing 488:= {1, 2, 3} 420:NP-complete 412:NP-complete 18:Hitting set 4017:Categories 3912:1581136749 3543:Alon, Noga 3536:References 3501:1601.02939 3138:Edge cover 3044:to get an 1275:relaxation 67:{1, 2, …, 3937:ϵ 3738:0004-5411 3670:0004-5411 3648:CiteSeerX 3585:1549-6325 3563:CiteSeerX 3311:0304-3975 3061:⁡ 2972:Δ 2969:⁡ 2917:Δ 2914:⁡ 2908:⁡ 2896:− 2893:Δ 2890:⁡ 2867:Δ 2837:ϵ 2834:− 2819:. If the 2807:ϵ 2804:− 2798:− 2737:⁡ 2731:⋅ 2709:− 2600:⁡ 2594:⋅ 2562:⁡ 2556:⋅ 2534:− 2504:, unless 2487:⁡ 2478:≈ 2470:⁡ 2320:≥ 2275:∈ 2213:Θ 2201:⁡ 2194:⁡ 2188:− 2180:⁡ 2057:… 1944:… 1893:… 1837:− 1772:⁡ 1696:⁡ 1670:− 1667:δ 1625:′ 1595:′ 1551:⁡ 1545:≤ 1515:∑ 1289:⁡ 1235:⁡ 1197:≤ 1184:≤ 1121:∈ 1042:∈ 1035:∑ 1005:⩾ 856:∈ 816:∈ 771:∈ 743:⩾ 725:∈ 719:: 712:∑ 661:∈ 654:∑ 643:minimize 228:⊆ 211:set cover 3966:(2001), 3926:(2008), 3891:(2003), 3863:citation 3795:(2001), 3754:Raz, Ran 3678:52827488 3615:(2001), 3593:11922650 3471:68396743 3034:Relaxing 2648:≠ 2617:, where 2335:for all 1750:with k=3 1389:, where 1083:, where 845:for all 760:for all 434:Variants 359:or less. 75:universe 61:Given a 3746:9021065 3526:9240467 3518:3590650 3392:3689577 2932:unless 2754:unless 1467:is the 1251:(where 637:(ILP). 446:In the 438:In the 424:NP-hard 3986:  3909:  3829:  3808:  3768:  3744:  3736:  3695:  3676:  3668:  3650:  3623:  3591:  3583:  3565:  3524:  3516:  3469:  3390:  3349:  3309:  3193:cover. 2250:using 1659:. For 1612:where 54:, and 3844:(PDF) 3802:(PDF) 3742:S2CID 3674:S2CID 3589:S2CID 3522:S2CID 3496:arXiv 3388:JSTOR 3285:(PDF) 3219:Notes 3038:above 2514:Feige 2416:When 2365:above 87:union 3984:ISBN 3907:ISBN 3869:link 3827:ISBN 3806:ISBN 3766:ISBN 3734:ISSN 3693:ISBN 3666:ISSN 3621:ISBN 3581:ISSN 3467:OCLC 3347:ISBN 3307:ISSN 2508:has 2481:0.72 2109:and 1724:> 1487:-th 629:The 209:, a 130:and 58:. 38:The 3976:doi 3953:doi 3899:doi 3852:doi 3724:doi 3658:doi 3573:doi 3506:doi 3420:doi 3380:doi 3297:doi 3293:246 3106:. 3058:log 3017:. 2461:log 2339:in 1763:log 1339:or 1286:log 1232:log 271:. 63:set 4019:: 3982:, 3970:, 3922:; 3905:, 3887:; 3883:; 3879:; 3865:}} 3861:{{ 3846:, 3756:; 3740:, 3732:, 3720:41 3718:, 3708:; 3672:, 3664:, 3656:, 3644:45 3642:, 3611:; 3607:; 3603:; 3587:, 3579:, 3571:, 3557:, 3549:; 3545:; 3520:, 3514:MR 3512:, 3504:, 3492:31 3490:, 3386:, 3374:, 3335:; 3331:; 3327:; 3305:. 3291:. 3287:. 2966:ln 2956:NP 2911:ln 2905:ln 2887:ln 2853:. 2780:. 2778:NP 2734:ln 2687:. 2661:NP 2597:ln 2559:ln 2506:NP 2484:ln 2254:. 2234:. 2198:ln 2191:ln 2177:ln 1739:. 1693:ln 1548:ln 1491:: 1343:. 1212:. 1140:. 1020:. 875:. 430:. 71:} 50:, 46:, 3978:: 3955:: 3901:: 3871:) 3854:: 3788:. 3775:. 3749:. 3726:: 3681:. 3660:: 3596:. 3575:: 3559:2 3508:: 3498:: 3473:. 3422:: 3382:: 3376:4 3313:. 3299:: 3208:. 3161:d 3156:R 3113:) 3109:( 3067:) 3064:n 3055:( 3052:O 3024:) 3020:( 2978:1 2975:+ 2943:= 2934:P 2920:) 2902:( 2899:O 2831:f 2801:1 2795:f 2765:= 2756:P 2741:n 2726:) 2721:) 2718:1 2715:( 2712:o 2706:1 2701:( 2671:c 2639:P 2625:c 2604:n 2591:c 2566:n 2551:) 2546:) 2543:1 2540:( 2537:o 2531:1 2526:( 2491:n 2474:n 2465:2 2454:2 2451:1 2424:n 2407:. 2405:O 2401:f 2396:S 2392:x 2388:S 2381:L 2377:O 2369:L 2349:S 2337:S 2323:0 2315:S 2311:x 2290:} 2287:1 2284:, 2281:0 2278:{ 2270:S 2266:x 2248:f 2244:f 2222:) 2219:1 2216:( 2210:+ 2205:n 2184:n 2150:3 2147:= 2144:k 2122:1 2118:T 2095:0 2091:T 2068:1 2064:S 2060:, 2054:, 2049:k 2045:S 2022:i 2018:S 1995:1 1991:T 1987:, 1982:0 1978:T 1955:k 1951:2 1947:, 1941:, 1938:8 1935:, 1932:4 1929:, 1926:2 1904:k 1900:S 1896:, 1890:, 1885:1 1881:S 1860:k 1840:2 1832:) 1829:1 1826:+ 1823:k 1820:( 1816:2 1812:= 1809:n 1789:2 1785:/ 1781:) 1778:n 1775:( 1767:2 1727:0 1721:c 1700:m 1690:c 1647:S 1621:s 1600:) 1591:s 1587:( 1584:H 1562:1 1559:+ 1555:n 1540:k 1537:1 1530:n 1525:1 1522:= 1519:k 1511:= 1508:) 1505:n 1502:( 1499:H 1475:n 1455:) 1452:n 1449:( 1446:H 1426:) 1423:n 1420:( 1417:H 1397:s 1377:) 1374:s 1371:( 1368:H 1292:n 1260:n 1238:n 1200:1 1192:s 1188:x 1181:0 1159:s 1155:x 1126:S 1118:s 1096:s 1092:w 1069:s 1065:x 1059:s 1055:w 1047:S 1039:s 1008:1 1002:x 999:A 978:0 975:= 970:s 967:, 964:e 960:A 937:1 934:= 929:s 926:, 923:e 919:A 896:A 861:S 853:s 831:} 828:1 825:, 822:0 819:{ 811:s 807:x 776:U 768:e 746:1 738:s 734:x 728:s 722:e 716:s 678:s 674:x 666:S 658:s 613:e 606:t 599:v 493:S 486:U 480:x 476:x 460:S 394:) 389:S 384:, 379:U 374:( 347:k 327:k 307:) 302:S 297:, 292:U 287:( 257:U 233:S 223:C 195:U 171:S 147:U 132:S 128:U 120:U 116:S 112:m 106:S 99:U 91:S 83:m 79:S 69:n 20:)

Index

Hitting set

combinatorics
computer science
operations research
complexity theory
set
universe
union
decision problem
optimization problem
NP-complete
Karp's 21 NP-complete problems
NP-complete
NP-hard
approximation algorithms
Covering/packing-problem pairs
Covering problems
Packing problems
Minimum set cover
Maximum set packing
Minimum edge cover
Maximum matching
Minimum vertex cover
Maximum independent set
Bin covering
Bin packing
Polygon covering
Rectangle packing
v

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