POJ

题目链接：http://poj.org/problem?id=1287

Sample Input

1 0

2 3
1 2 37
2 1 17
1 2 68

3 7
1 2 19
2 3 11
3 1 7
1 3 5
2 3 89
3 1 91
1 2 32

5 7
1 2 5
2 3 7
2 4 8
4 5 11
3 5 10
1 5 6
4 2 12

0
Sample Output

0
17
16
26

分析：最小生成树纯模板

#include <cstdio>
#include <cstring>
#include <iostream>
#include <cmath>
using namespace std;
#define N 110
#define met(a, b) memset(a, b, sizeof(a))
#define INF 0x3f3f3f3f


int n, m, dist[N], Maps[N][N], vis[N];

int Prim(int s)
{
    vis[s] = 1;
    for(int i=1; i<=n; i++)
    {
        dist[i] = Maps[s][i];
    }
    int sum = 0;
    for(int i=1; i<n; i++)
    {
        int Min = INF, Index = -1;
        for(int j=1; j<=n; j++)
        {
            if(!vis[j] && Min>dist[j])
            {
                Min = dist[j];
                Index = j;

            }
        }
        sum += Min;
        vis[Index] = 1;
        for(int j=1; j<=n; j++)
        {
            if(!vis[j] && dist[j]>Maps[Index][j])
            {
                dist[j] = Maps[Index][j];
            }
        }

    }
    return sum;
}

void Init()
{
    for(int i=0; i<=n; i++)
    {
        for(int j=0; j<=n; j++)
            Maps[i][j] = (i==j)?0:INF;
        dist[i] = INF;
        vis[i] = 0;
    }
}

int main()
{
    while(scanf("%d", &n), n)
    {
        int u, v, w;
        Init();
        scanf("%d", &m);
        for(int i=1; i<=m; i++)
        {
            scanf("%d %d %d", &u, &v, &w);
            Maps[u][v] = Maps[v][u] = min(Maps[u][v], w);
        }
        int ans = Prim(1);

        printf("%d
", ans);
    }
    return 0;
}