POJ 1258

//11132194c00h00g1258Accepted764K16MSG++1238B2012-12-23 16:07:01#include<stdio.h>#include<stdlib.h>#include<queue>#include<algorithm>using namespace std;int N;struct Edge{    int from,to,w;    Edge(int x,int y,int z):from(x),to(y),w(z){}    bool operator<(const Edge& rhs) const{        return w>rhs.w;    }};priority_queue<Edge> q;int parent[105];void makeset(int i){parent[i]=i;}int findset(int i){return i!=parent[i]?parent[i]=findset(parent[i]):i;}void unionset(int x,int y){    if(x<y)        parent[y]=x;    else         parent[x]=y;}__int64 kruskal(){    __int64 res=0;    for(int i=0;i<N;i++)        makeset(i);    while(!q.empty()){        Edge edge=q.top();q.pop();        int x=findset(edge.from);        int y=findset(edge.to);        if(x!=y){            res+=edge.w;            unionset(x,y);        }    }        return res;}int main(){    while(scanf("%d",&N)!=EOF){        while(!q.empty())            q.pop();        for(int i=0;i<N;i++)            for(int j=0;j<N;j++){                int weight;                scanf("%d",&weight);                if(i<=j)                    q.push(Edge(i,j,weight));            }        printf("%I64d\n",kruskal());    }    return 0;}