洛谷P1529 回家 Bessie Come Home

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

int p,flag[210],map[210][210];

int main()
{
    for (int i = 'A'; i <= 'z'; i++)
    for (int j = 'A'; j <= 'z'; j++)
    if (i != j)
    map[i][j] = 100000000;
    scanf("%d
",&p);
    for (int i = 1; i <= p; i++)
    {
        char a,b;
        int c;
        scanf("%c %c %d
",&a,&b,&c);
        if (a >= 'A' && a <= 'Z')
        flag[a] = 1;
        if (b >= 'A' && b <= 'Z')
        flag[b] = 1;
        map[a][b] = map[b][a] = min(c,map[a][b]);
    }
    for (int k = 'A'; k <= 'z'; k++)
    for (int i = 'A'; i <= 'z'; i++)
    for (int j = 'A'; j <= 'z'; j++)
    map[i][j] = min(map[i][j],map[i][k] + map[k][j]);
    int ans = 100000000;
    char ans1;
    for (int i = 'A'; i <= 'Y'; i++)
    if (flag[i] && map[i]['Z'] < ans)
    {
        ans = map[i]['Z'];
        ans1 = char(i);
    }
    printf("%c %d",ans1,ans);
    
    return 0;
}