http://acm.hdu.edu.cn/showproblem.php?pid=1233&&Krusal

算是水题。。。。。但自己感觉水的不太好(*^__^*) 嘻嘻……come on#include<iostream> #include<string.h> #include<algorithm> #include<limits.h> #define N 5005 #define FOR(i,s,t) for(int i=(s);i<=t;++i) using namespace std; int n,m; int father[N]; struct edge{int x,y,len; }map[N]; typedef struct edge Node; int cmp(const void *a,const void *b) { return ((Node*)a)->len>((Node*)b)->len?1:-1; } void make_set() { FOR(i,1,n) father[i]=i; } int find_set(int a) { while(a!=father[a]) a=father[a]; return a; } void Kursal() { int sum=0,ans=0; FOR(i,1,m) { int x=find_set(map[i].x); int y=find_set(map[i].y); if(x!=y) { father[y]=x; sum+=map[i].len; ans++; } if(ans==n-1) break; } cout<<sum<<endl; } int main() { while(cin>>n&&n) { m=n*(n-1)/2; make_set(); FOR(i,1,m) cin>>map[i].x>>map[i].y>>map[i].len; qsort(map+1,m,sizeof(Node),cmp); Kursal(); } return 0; }