小镇网（最小生成树）

#include <stdio.h>
#include <string.h>
#define MAX_NUM 105
int map[MAX_NUM][MAX_NUM], n;
int prime()
{
    int pos, min, result = 0, visited[MAX_NUM], low[MAX_NUM];
    memset(visited, 0, sizeof(visited));
    visited[1] = 1;  
    pos = 1;        
    for(int i = 1; i <= n; i++)
        if(i != pos)
            low[i] = map[pos][i];
    for(int i = 1; i < n; i++)
    {
        min = 100000000;
        for(int j = 1; j <= n; j++)
        {
            if(visited[j] == 0 && low[j] < min)
            {
                min = low[j];
                pos = j;
            }
        }
        result += min;
        visited[pos] = 1;
        for(int j = 1; j <= n; j ++)
        {
            if(visited[j] == 0 && low[j] > map[pos][j])
                low[j] = map[pos][j];
        }
    }
    return result;
}
int main()
{
    scanf("%d", &n);
    for(int i = 1; i <= n; i++)
        for(int j = 1; j <=n; j++)
        {
            scanf("%d", &map[i][j]);
            if(map[i][j] == 0)
                map[i][j] = 1000000;
        }
    printf("%d\n", prime());
    return 0;
}