Uva1395slim Span (enumeration minimum spanning tree)

Test instructions: In the minimum spanning tree, the largest edge minus the minimum edge minimum value.

It's easy to see the =_=.

Sort each edge from small to large and then enumerate the smallest spanning tree from smallest to largest, updating the minimum when forming a spanning tree

1#include <iostream>2#include <cstdio>3#include <cstring>4#include <algorithm>5 using namespacestd;6 Const intINF =0x3f3f3f3f;7 Const intMax = the;8 Const intN = the;9 intFather[n];Ten structEdge One { A     intx, Y, Dist; - }; - Edge Edge[max]; the intcmp (Edge t1, Edge T2) - { -     returnT1.dist <t2.dist; - } + intFind_father (intx) - { +     if(x = =Father[x]) A         returnx; at     returnFATHER[X] =Find_father (father[x]); - } - intMain () - { -     intN, M; -      while(SCANF ("%d%d", &n, &m)! =EOF) in     { -         if(M = =0&& n = =0) to              Break; +          for(inti =0; I < m; i++) -         { thescanf"%d%d%d", &edge[i].x, &AMP;EDGE[I].Y, &edge[i].dist); *         } $Sort (edge, Edge +m, CMP);Panax Notoginseng         intMinn =INF; -          for(inti =0; I < m; i++) the         { +              for(intj =0; J <= N; J + +) AFATHER[J] =J; the             intCNT =0; +              for(intj = i; J < M; J + +)//enumerate each spanning tree in turn -             { $                 intFX =Find_father (edge[j].x); $                 intFY =Find_father (EDGE[J].Y); -                 if(FX! =fy) -                 { theFATHER[FX] =fy; -cnt++;Wuyi                     if(cnt = = N-1)//Once the spanning tree is formed, j is the maximum edge, I is the least weight, and the subtraction is updated the                     { -Minn = MIN (minn, edge[j].dist-edge[i].dist); Wu                          Break; -                     } About                 } $             } -         } -         if(Minn = =INF) -printf"-1\n"); A         Else +printf"%d\n", Minn); the     } -     return 0; $}

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Uva1395slim Span (enumeration minimum spanning tree)