PoJ(2263)，Floyd，最小值中的最大值

题目链接：http://poj.org/problem?id=2263

题意：题中给出相连通不同城市之间的载货量，要求找到一条从指定起点到终点的路径，并满足载货量最大。

#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
using namespace std;
const int POINT = 210;

int dis[POINT][POINT];
string city[POINT];
int main()
{
    int cases = 0;
    int n,r;
    while(scanf("%d %d",&n,&r),n||r)
    {
        cases++;
        memset(dis,0,sizeof(dis));
        int numcity = 1;
        for(int i=1; i<=r; i++)
        {
            string a,b;
            int w;
            cin>>a>>b>>w;
            int u=0,v=0;
            for(int j=1; j<=numcity; j++)
            {
                if(a==city[j])
                    u = j;
                if(b==city[j])
                    v = j;
            }
            if(u==0)
            {
                u = numcity;
                city[numcity++] = a;
            }
            if(v==0)
            {
                v = numcity;
                city[numcity++] = b;
            }
            dis[u][v] = dis[v][u]  = w;
        }

        for(int k=1;k<=n;k++)
        {
            for(int i=1;i<=n;i++)
            {
                for(int j=1;j<=n;j++)
                    dis[i][j] = max(dis[i][j],min(dis[i][k],dis[k][j]));
            }
        }

        string a,b;
        cin>>a>>b;
        int u,v;
        for(int i=1; i<=n; i++)
        {
            if(a == city[i])
                u = i;
            if(b == city[i])
                v = i;
        }
        printf("Scenario #%d\n%d tons\n\n",cases,dis[u][v]);
        for(int i=1;i<=n;i++)
            city[i].clear();
    }
}