Usaco2.44Bessie Come Home(floyd)

floyd之后 枚举找最小就行 会有重边

/*
      ID: shangca2
      LANG: C++
      TASK: comehome
*/
#include <iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<stdlib.h>
#define INF 0x3f3f3f
using namespace std;
int w[110][110];
int main()
{
    freopen("comehome.in","r",stdin);
    freopen("comehome.out","w",stdout);
    int i,j,k,n,d,a,b,m=52;
    char c1,c2,c;
    cin>>n;
    for(i = 0 ; i < m ;i++)
        for(j = 0 ; j < m ; j++)
        w[i][j] = INF;
    for(i = 0 ; i < n ; i++)
    {
        cin>>c1>>c2>>d;
        if(c1>='A'&&c1<='Z')
        a = c1-'A';
        else
        a = c1-'a'+26;
        if(c2>='A'&&c2<='Z')
        b = c2-'A';
        else
        b = c2-'a'+26;
        if(w[a][b]>d)
        {
            w[a][b] = d;
            w[b][a] = d;
        }
    }
    for(i = 0 ; i < m ; i++)
    w[i][i] = 0;
    for(i = 0 ; i < m ; i++)
        for(j = 0 ; j < m ; j++)
            for(k = 0 ; k < m ; k++)
            if(w[j][k]>w[j][i]+w[i][k])
            w[j][k] = w[j][i]+w[i][k];
    int ans = INF;
    for(i = 0 ; i < 25 ; i++)
    {
        if(w[i][25]<ans)
        {
            c = i+'A';
            ans = w[i][25];
        }
    }
    cout<<c<<" "<<ans<<endl;
    return 0;
}