[Usaco3.1.1]agrinet

is a template problem of the smallest spanning tree, and by the way it learns the Rujia and Kruskal algorithms.

1 /*2 id:abc312613 lang:c++4 task:agrinet5 */6#include <cstdio>7#include <cstring>8#include <algorithm>9#include <iostream>Ten using namespacestd; One Const intmaxn=11111; A intR[MAXN],F[MAXN],W[MAXN],U[MAXN],V[MAXN]; -  - intcmpConst intIConst intj) {returnw[i]<w[j];} {Indirect sort} the  - intFindintx) - { -     if(f[x]!=x) f[x]=find (F[x]); +     returnF[x]; - } + intMain () A { at     inti,j,l,x,y,n,m=0, ans=0; -Freopen ("agrinet.in","R", stdin); -Freopen ("Agrinet.out","W", stdout); -scanf"%d",&n); -      for(i=1; i<=n;i++) -          for(j=1; j<=n;j++) in         { -scanf"%d",&l); tow[++m]=l; +u[m]=i; -v[m]=J; the         } *      for(i=1; i<=m;i++) r[i]=f[i]=i; $Sort (r+1, r+m+1, CMP);Panax Notoginseng      for(i=1; i<=m;i++) -     { theJ=r[i]; X=find (U[j]); y=find (V[j]); +         if(x!=y) A         { theans+=W[j]; +f[y]=x; -         } $     } $printf"%d\n", ans); -     return 0; -}

[Usaco3.1.1]agrinet