POJ2421 最小生成树/MST(prim)

#include <iostream>
#include <cstdio>
#include <queue>
#include <cstring>
using namespace std;
const int MAXN=110;
const int INF=100000000;
int dist[MAXN];
struct cedge
{
int to;
int w;
cedge(int _to=0,double _w=INF)
{
to=_to;
w=_w;
}
}edge;
bool operator<(const cedge &e1,const cedge &e2)
{
return e1.w>e2.w;
}
int MST(int n,int map[][110])
{
int ans;
int sum=n;
int i;
int  visit[110];
ans=0;
priority_queue<cedge> qu;
memset(visit,0,sizeof(visit));
qu.push(cedge(1,0));
memset(dist,127,sizeof(dist));
cedge current;
while(sum--)
{
do
{
current=qu.top();
qu.pop();
//	cout<<current.to<<"  "<<current.w<<endl;

}while(visit[current.to]==true&&!qu.empty());
visit[current.to]=true;
ans+=current.w;
for(i=0;i<n;i++)
{
if(visit[i+1]==false)
{
if(map[current.to-1][i]<dist[i+1])
{
dist[i+1]=map[current.to-1][i];
//	cout<<"dist: "<<i+1<<"  "<<dist[i+1]<<endl;
qu.push(cedge(i+1,dist[i+1]));
}

}
}

}
return ans;

}
int main()
{
int map[110][110];
int n;
int t;
int i,j;
int from;
int to;

while(scanf("%d",&n)!=EOF)
{

for(i=0;i<n;i++)
{
for(j=0;j<n;j++)
{
scanf("%d",&map[i][j]);
}
}
scanf("%d",&t);
for(i=0;i<t;i++)
{
scanf("%d %d",&from,&to);
from--;
to--;
map[from][to]=0;
map[to][from]=0;

}

int ans=MST(n,map);

printf("%d\n",ans);
}

return 0;
}