NYOJ434_Jungle Roads(最小生成树)

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用并查集实现克鲁斯卡尔算法，求最小生成树

#include<stdio.h>#include<algorithm>using namespace std;struct Edge{int u;int v;int cost;}e[1000];int p[500];int comp(Edge e1,Edge e2){return e1.cost<e2.cost;}int find(int x){if(p[x]!=x){p[x]=find(p[x]);}return p[x];}bool bin(int x,int y){int g=find(x);int h=find(y);if(g!=h){p[g]=h;return true;}return false;}bool check(int n){int i,res=0;for(i=1;i<=n;i++){if(p[i]==i)res++;}if(res>1)return false;return true;}int main(){int n,i,m,j,u,v,cost,size,res;char ch[2];while(scanf("%d",&n)&&n!=0){res=0;size=0;for(i=1;i<=n;i++){p[i]=i;}for(i=1;i<n;i++){u=i;getchar();scanf("%s%d",&ch,&m);for(j=0;j<m;j++){getchar();scanf("%s%d",&ch,&cost);e[size].u=i;e[size].v=ch[0]-'A'+1;e[size++].cost=cost;}}sort(e,e+size,comp);for(i=0;i<size;i++){if(bin(e[i].u,e[i].v)){res+=e[i].cost;if(check(n))break;}}printf("%d\n",res);}return 0;}

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