HDOJ1102 修路问题（最小生成树-Prim）

#include <cstdio>
#include <cstring>
#include <iostream>
using namespace std;

#define M 100
#define MAX 9999

int map[M][M],visited[M],adjset[M];
int n,p,len;

void ReadMap();

void main()
{
int i,j,nlen,nid;
while (scanf("%d",&n)!=EOF)
{
//读取地图
ReadMap();
//初始化
memset(visited,0,sizeof(visited));
visited[0] = 1;
len = 0;
for (i=0;i<n;i++)    adjset[i] = map[i][0];
//Begin
for (i=1;i<n;i++)
{
//找到下一条符合条件的点
nlen = MAX;
for (j=0;j<n;j++)
{
if (!visited[j] && adjset[j]<nlen)
{
nlen = adjset[j];
nid = j;
}
}
//访问找到的那个点
len += nlen;
visited[nid] = 1;
//更新邻接距离
for (j=0;j<n;j++)
{
if (!visited[j] && map[j][nid]<adjset[j])
{
adjset[j] = map[j][nid];
}
}
}
cout<<len<<endl;
}
}

void ReadMap()
{
int i,j,a,b;
for (i=0;i<n;i++)
{
for (j=0;j<n;j++)
{
cin>>map[i][j];
}
}
cin>>p;
for (i=0;i<p;i++)
{
cin>>a>>b;
map[a-1][b-1] = map[b-1][a-1] = 0;
}
}