UVA 10048 - Audiophobia

这道题和刚才那道题不同，求的是最大边的最小值。同样用了floyd算法

d[i][j]=min{d[i][j],max{d[i][k],d[k][j]}}

Initilization: d[1..n][1..n]= -1,d[i][i]=0;

 

#include<stdio.h>
#define MAXD 105
int u, v, w, C, S, Q, q[10005];
int d[MAXD][MAXD];
int max( int a, int b)
{
    return a > b ? a : b;
}

void init()
{
    for( int i = 1; i <= C; i ++)
        for( int j = 1; j <= C; j ++)
        {
            if( i == j) d[i][j] = 0;
            else d[i][j] = -1;
        }
    for( int i = 0; i < S; i ++)
    {
        scanf( "%d%d%d", &u, &v, &w);
        d[u][v] = d[v][u] = w;
    }
}

void floyd()
{
    for( int k = 1; k <= C; k ++)
        for( int i = 1; i <= C; i ++)
            for( int j = 1; j <= C; j ++)
                if(  d[i][k] != -1 && d[k][j] != -1)
                {
                    int temp = max( d[i][k], d[k][j]);
                    if( d[i][j] == -1 || d[i][j] > temp )
                        d[i][j] = temp;
                }
}

int main()
{
    int cas = 0;
    while( true)
    {
        scanf( "%d%d%d", &C, &S, &Q);
        if( C == 0 && S == 0 && Q == 0) break;
        init();
        floyd();
        if( cas ++) printf( "\n");
        printf( "Case #%d\n", cas);
        for( int i = 1; i <= Q; i ++)
        {
            scanf( "%d%d", &u, &v);
            q[i] = d[u][v];
        }
        for( int i = 1; i <= Q; i ++)
        {
            if( q[i] == -1)
                printf( "no path\n");
            else
                printf( "%d\n", q[i]);
        }
    }
    return 0;
}

http://hi.baidu.com/knowledgetime/blog/item/6c6c71c1b30d703ae5dd3bdb.html