poj-2395

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求最小生成树的最大边 ，初始值设一千万还是WA也是醉了，看了解题报告才发现必须足够大才可以。

#include <stdio.h>
#include <iostream>
#include <string.h>
#include <algorithm>
#include <stdlib.h>

using namespace std;

int vis[10010];
int low[10010];
int p[2010][2010];

int i,j,k;
int minn ,pos;

int n,m;

int prim()
{
    int ans = -0x7fffffff;
    memset (vis,0,sizeof(vis));
    pos=1;
    vis[1]=1;
    for (i =1;i<=n;i++)
    {
        if (i!=pos)
            low[i] = p[i][pos];
    }
    for (i=1;i<n;i++)
    {
        minn = 0x7fffffff;
        for (int i=1;i<=n;i++)
        {
            if (!vis[i] && minn > low[i])
            {
                minn = low[i];
                pos = i;
            }
        }
        ans = max (minn,ans);
        vis[pos]=1;
        for (int i=1;i<=n;i++)
        {
            if (!vis[i] && low[i] > p[i][pos])
                low[i]=p[pos][i];
        }
    }
    return ans;
}

int main()
{
    while (scanf ("%d%d",&n,&m)!=EOF)
    {
        int c,d,e;

        for ( i =1;i<=n;i++)
            for( j=1;j<=n;j++)
        {
            if (i == j)
                p[i][j] = 0;
            else
                p[i][j] =0x7fffffff;
        }

        for (i =1;i<=m;i++)
        {
            scanf ("%d%d%d",&c,&d,&e);
            if (p[c][d] > e)
                p[c][d]=p[d][c]=e;
        }
        int res = prim();
        printf("%d\n",res);
    }
    return 0;
}