POJ 1797 Heavy Transportation

#include<stdio.h>
#define INF 0x3f3f3f3f
#define N 1100
#define min(a, b) (a < b ? a : b)
#define max(a, b) (a > b ? a : b)
int G[N][N], dist[N], visit[N], n; //dist数组存放的是所有从1到i路径之间的每一小段的最小值的最大值
void Init()
{
    int i, j;
    for (i = 0; i <= n; i++)
    {
        visit[i] = 0;
        dist[i] = -INF;
        for (j = 0; j <= n; j++)
            G[i][j] = -INF; 
    }
}
void Dist()
{
    int i, j, idex, Min;
    dist[1] = 0;
    for (i = 1; i <= n; i++)
    {
        Min = -INF;
        for (j = 1; j <= n; j++)
        {
            if (dist[j] > Min && !visit[j])
            {
                Min = dist[j];
                idex = j;
            }
        }
        visit[idex] = 1;
        for (j = 1; j <= n; j++)
        {
            if (idex == 1)
            {
                if (!visit[j] && dist[j] < max(dist[idex], G[idex][j]))
                    dist[j] = max(dist[idex], G[idex][j]);
            } //如果idex是1时仍然用min，则dist数组中都是0，为了不影响结果要max，这样dist数组就不会全是0了
            else
            {
                if (!visit[j] && dist[j] < min(dist[idex], G[idex][j]))
                    dist[j] = min(dist[idex], G[idex][j]);
            }
        }
    }
}
int main ()
{
    int T, m, a, b, c, k = 0;
    scanf("%d", &T);
    while (T--)
    {
        Init();
        k++;
        scanf("%d %d", &n, &m);
        while (m--)
        {
            scanf("%d %d %d", &a, &b, &c);
            G[a][b] = max(G[a][b], c);
            G[b][a] = G[a][b];
        }
        Dist();
        printf("Scenario #%d:\n", k);
        printf("%d\n", dist[n]);
        printf("\n");
    }
    return 0;
}