POJ 2263 Heavy Cargo（Floyd + map）

#include <cstdio>
#include <iostream>
#include <cstdlib>
#include <algorithm>
#include <ctime>
#include <cmath>
#include <string>
#include <cstring>
#include <stack>
#include <queue>
#include <list>
#include <vector>
#include <map>
#include <set>
using namespace std;

const int INF=0x3f3f3f3f;
const double eps=1e-10;
const double PI=acos(-1.0);
#define maxn 500

map<string, int> a;
char s1[32];
char s2[32];
int  c[maxn][maxn];
int v[maxn][maxn];
int pre[maxn][maxn];
int main()
{
    int n, m, w;
    int cas = 0;
    while(~scanf("%d%d",&n,&m)&&(n+m))
    {
        int cnt = 0;
        memset(c, 0, sizeof c);
        for(int i = 0; i < m; i++)
        {
            scanf("%s%s%d", s1, s2, &w);
            if(!a.count(s1))
            a[s1] = cnt++;
            if(!a.count(s2))
            a[s2] = cnt++;
            c[a[s1]][a[s2]] = c[a[s2]][a[s1]] = w;
        }
//    map<string, int>::iterator it;
//    for(it=a.begin();it!=a.end();++it)
//        cout<<"key: "<<it->first <<" value: "<<it->second<<endl;
        for(int i = 0; i < n; i++)
            for(int j = 0; j < n; j++)
            {
                v[i][j] = c[i][j];
                pre[i][j] = i;
            }

        for(int k = 0; k < n; k++)
            for(int i = 0; i<n; i++)
                for(int j = 0; j < n; j++)
                {
                    v[i][j] = max(v[i][j], min(v[i][k],v[k][j]));
                    pre[i][j] = pre[k][j];
                }

        scanf("%s%s",s1,s2);

        printf("Scenario #%d\n", ++cas);
        printf("%d tons\n",v[a[s1]][a[s2]]);
        puts("");
    }
    return 0;
}