Knowledge (XXG)

Cut (graph theory)

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is to bipartition the vertices so as to minimize the ratio of the number of edges across the cut divided by the number of vertices in the smaller half of the partition. This objective function favors solutions that are both sparse (few edges crossing the cut) and balanced (close to a bisection). The
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if the size or weight of the cut is not larger than the size of any other cut. The illustration on the right shows a minimum cut: the size of this cut is 2, and there is no cut of size 1 because the graph is
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if the size of the cut is not smaller than the size of any other cut. The illustration on the right shows a maximum cut: the size of the cut is equal to 5, and there is no cut of size 6, or |
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A cut is a partition of the nodes of a graph into two sets. The cut size is the sum of the weights of the edges "between" the two sets of nodes.
927: 66:, each cut-set determines a unique cut, and in some cases cuts are identified with their cut-sets rather than with their vertex partitions. 953: 881: 812: 688: 650: 374: 738: 553: 769:(1995), "Improved approximation algorithms for maximum cut and satisfiability problems using semidefinite programming", 264: 47: 948: 548: 329: 641: 324:
and the sum of the cut-edge weights of any minimum cut that separates the source and the sink are equal. There are
523:. Each edge of this tree is associated with a bond in the original graph, and the minimum cut between two nodes 390: 317: 84: 78: 512: 435: 568: 504: 310: 43: 628: 558: 500: 766: 516: 386: 382: 58:, the set of edges that have one endpoint in each subset of the partition. These edges are said to 520: 852: 771: 496: 408: 404: 400: 39: 923: 877: 871: 808: 707:(1972), "Reducibility among combinatorial problems", in Miller, R. E.; Thacher, J. W. (eds.), 684: 646: 898: 680: 844: 780: 670: 666: 632: 624: 563: 363: 325: 63: 373:
In general, finding a maximum cut is computationally hard. The max-cut problem is one of
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sense, even though one gets from one problem to other by changing min to max in the
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problem is known to be NP-hard, and the best known approximation algorithm is an
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only consists of edges going from the source's side to the sink's side. The
511:. If the edges of the graph are given positive weights, the minimum weight 922:, Algorithms and Combinatorics, vol. 21, Springer, pp. 180–186, 785: 735:
Proceedings of the 45th IEEE Symposium on Foundations of Computer Science
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Gross, Jonathan L.; Yellen, Jay (2005), "4.6 Graphs and Vector Spaces",
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is the minimum weight bond among the ones associated with the path from
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of an s–t cut is defined as the sum of the capacity of each edge in the
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Computers and Intractability: A Guide to the Theory of NP-Completeness
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is a cut-set that does not have any other cut-set as a proper subset.
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is defined by the sum of the weights of the edges crossing the cut.
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The family of all cut sets of an undirected graph is known as the
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of two cut sets as the vector addition operation, and is the
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of a cut is the number of edges crossing the cut. In a
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Diestel, Reinhard (2012), "1.9 Some linear algebra",
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Partition of a graph's nodes into 2 disjoint subsets
463: 362:| (the number of edges), because the graph is not 328:methods to solve the min-cut problem, notably the 920:Combinatorial Optimization: Theory and Algorithms 726:; Kindler, G.; Mossel, E.; O’Donnell, R. (2004), 519:on the same vertex set as the graph, called the 472: 918:; Vygen, Jens (2008), "8.6 Gomory–Hu Trees", 876:(2nd ed.), CRC Press, pp. 197–207, 8: 784: 711:, New York: Plenum Press, pp. 85–103 445: 437: 584: 515:of the cut space can be described by a 255:In an unweighted undirected graph, the 7: 221:are specified vertices of the graph 89:to be in different subsets, and its 464:{\displaystyle O({\sqrt {\log n}})} 205:of edges that have one endpoint in 709:Complexity of Computer Computation 396:Note that min-cut and max-cut are 25: 873:Graph Theory and Its Applications 597:networkx.algorithms.cuts.cut_size 473:Arora, Rao & Vazirani (2009) 744:from the original on 2019-07-15 603:from the original on 2021-11-18 593:"NetworkX 2.6.2 documentation" 458: 442: 377:. The max-cut problem is also 375:Karp's 21 NP-complete problems 1: 554:Graph cuts in computer vision 807:, Springer, pp. 97–98, 549:Connectivity (graph theory) 415:problem is the dual of the 77:is a cut that requires the 970: 954:Combinatorial optimization 642:Introduction to Algorithms 347: 297: 209:and the other endpoint in 487:of the graph. It forms a 805:Approximation Algorithms 391:semidefinite programming 320:proves that the maximum 318:max-flow min-cut theorem 849:10.1145/1502793.1502794 681:A2.2: ND16, p. 210 54:. Any cut determines a 465: 345: 330:Edmonds–Karp algorithm 295: 786:10.1145/227683.227684 629:Leiserson, Charles E. 569:Bridge (graph theory) 505:orthogonal complement 491:over the two-element 471:approximation due to 466: 343: 293: 737:, pp. 146–154, 559:Split (graph theory) 501:symmetric difference 436: 429:sparsest cut problem 387:approximation ratio 248:belongs to the set 240:belongs to the set 949:Graph connectivity 801:Vazirani, Vijay V. 772:Journal of the ACM 461: 409:objective function 405:linear programming 346: 296: 236:is a cut in which 127:is a partition of 929:978-3-540-71844-4 767:Williamson, D. P. 671:Johnson, David S. 667:Garey, Michael R. 633:Rivest, Ronald L. 625:Cormen, Thomas H. 456: 146:into two subsets 16:(Redirected from 961: 934: 932: 912: 906: 904: 894: 888: 886: 867: 861: 859: 843:(2), ACM: 1–37, 825: 819: 817: 797: 791: 789: 788: 779:(6): 1115–1145, 759: 753: 751: 750: 749: 743: 732: 720: 714: 712: 701: 695: 693: 679:, W.H. Freeman, 663: 657: 655: 621: 615: 614: 609: 608: 589: 564:Vertex separator 470: 468: 467: 462: 457: 446: 418: 414: 403:problems in the 383:P = NP 251: 247: 243: 239: 233: 229: 224: 220: 216: 212: 208: 204: 172: 153: 149: 145: 130: 126: 52:disjoint subsets 21: 969: 968: 964: 963: 962: 960: 959: 958: 939: 938: 937: 930: 914: 913: 909: 896: 895: 891: 884: 869: 868: 864: 833:Vazirani, Umesh 831:; Rao, Satish; 827: 826: 822: 815: 799: 798: 794: 761: 760: 756: 747: 745: 741: 730: 722: 721: 717: 703: 702: 698: 691: 665: 664: 660: 653: 637:Stein, Clifford 623: 622: 618: 606: 604: 591: 590: 586: 582: 545: 481: 434: 433: 425: 416: 412: 352: 338: 326:polynomial-time 302: 288: 249: 245: 241: 237: 231: 227: 222: 218: 214: 210: 206: 174: 159: 151: 147: 132: 128: 113: 107: 64:connected graph 28: 23: 22: 15: 12: 11: 5: 967: 965: 957: 956: 951: 941: 940: 936: 935: 928: 907: 889: 882: 862: 829:Arora, Sanjeev 820: 813: 792: 763:Goemans, M. X. 754: 715: 696: 689: 658: 651: 616: 583: 581: 578: 577: 576: 571: 566: 561: 556: 551: 544: 541: 521:Gomory–Hu tree 499:two, with the 495:of arithmetic 480: 477: 460: 455: 452: 449: 444: 441: 424: 421: 348:Main article: 344:A maximum cut. 337: 334: 298:Main article: 294:A minimum cut. 287: 284: 265:weighted graph 106: 103: 62:the cut. In a 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 966: 955: 952: 950: 947: 946: 944: 931: 925: 921: 917: 911: 908: 902: 901: 893: 890: 885: 883:9781584885054 879: 875: 874: 866: 863: 858: 854: 850: 846: 842: 838: 834: 830: 824: 821: 816: 814:3-540-65367-8 810: 806: 802: 796: 793: 787: 782: 778: 774: 773: 768: 764: 758: 755: 740: 736: 729: 725: 719: 716: 710: 706: 700: 697: 692: 690:0-7167-1045-5 686: 682: 678: 677: 672: 668: 662: 659: 654: 652:0-262-03293-7 648: 644: 643: 638: 634: 630: 626: 620: 617: 613: 602: 598: 594: 588: 585: 579: 575: 572: 570: 567: 565: 562: 560: 557: 555: 552: 550: 547: 546: 542: 540: 539:in the tree. 538: 534: 530: 526: 522: 518: 514: 510: 506: 502: 498: 494: 490: 486: 478: 476: 474: 453: 450: 447: 439: 430: 422: 420: 410: 406: 402: 399: 394: 392: 388: 384: 380: 376: 371: 369: 366:(there is an 365: 361: 357: 351: 342: 335: 333: 331: 327: 323: 319: 314: 312: 307: 301: 292: 285: 283: 281: 276: 274: 270: 266: 262: 258: 253: 235: 202: 198: 194: 190: 186: 182: 178: 170: 166: 162: 157: 143: 139: 135: 124: 120: 116: 112: 104: 102: 100: 96: 92: 88: 87: 82: 81: 76: 72: 67: 65: 61: 57: 53: 49: 45: 41: 37: 33: 19: 919: 916:Korte, B. H. 910: 900:Graph Theory 899: 892: 872: 865: 840: 836: 823: 804: 795: 776: 770: 757: 746:, retrieved 734: 718: 708: 699: 674: 661: 640: 619: 611: 605:. Retrieved 596: 587: 536: 532: 528: 524: 493:finite field 489:vector space 484: 482: 428: 426: 423:Sparsest cut 397: 395: 372: 359: 355: 353: 322:network flow 315: 305: 303: 279: 277: 272: 268: 260: 256: 254: 226: 200: 196: 192: 188: 184: 180: 176: 168: 164: 160: 155: 141: 137: 133: 122: 118: 114: 110: 108: 98: 94: 90: 85: 79: 74: 71:flow network 68: 59: 55: 35: 32:graph theory 29: 705:Karp, R. M. 509:cycle space 350:Maximum cut 336:Maximum cut 300:Minimum cut 286:Minimum cut 173:is the set 131:of a graph 943:Categories 748:2019-08-29 607:2021-12-10 580:References 311:bridgeless 225:, then an 105:Definition 857:263871111 485:cut space 479:Cut space 451:⁡ 419:problem. 368:odd cycle 364:bipartite 354:A cut is 304:A cut is 158:of a cut 50:into two 40:partition 803:(2004), 739:archived 724:Khot, S. 673:(1979), 639:(2001), 601:Archived 574:Cutwidth 543:See also 413:max-flow 379:APX-hard 95:capacity 83:and the 44:vertices 507:of the 417:min-cut 356:maximum 306:minimum 156:cut-set 99:cut-set 91:cut-set 75:s–t cut 56:cut-set 42:of the 18:Cut set 926:  880:  855:  837:J. ACM 811:  687:  649:  497:modulo 411:. The 389:using 273:weight 267:, the 261:weight 154:. The 80:source 853:S2CID 742:(PDF) 731:(PDF) 513:basis 269:value 213:. 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Index

Cut set
graph theory
partition
vertices
graph
disjoint subsets
connected graph
flow network
source
sink
weighted graph

Minimum cut
bridgeless
max-flow min-cut theorem
network flow
polynomial-time
Edmonds–Karp algorithm

Maximum cut
bipartite
odd cycle
Karp's 21 NP-complete problems
APX-hard
P = NP
approximation ratio
semidefinite programming
dual
linear programming
objective function

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