1~26为a~z–空牧场 27~51为A~Y–有牛牧场 52为Z–牛棚

#include<stdio.h>
#include<string.h>
#include<stdbool.h>

#define N 53
#define INF 0x3f3f3f3f

int P;
int g[N][N];
int dist[N];
bool st[N];

int min(int a, int b){  return a < b ? a : b;  }

void dijkstra(int x){
    memset(dist, 0x3f, sizeof dist);
    dist[x] = 0;

    for(int i = 1; i <= 52; i++){

        int t = -1;
        for(int j = 1; j <= 52; j++)
            if(!st[j] && (t == -1 || dist[t] > dist[j]))
                t = j;

        st[t] = true;

        for(int j = 1; j <= 52; j++)
            dist[j] = min(dist[j], dist[t] + g[t][j]);
    }
}

int main(){

    scanf("%d", &P);
    memset(g, 0x3f, sizeof g);

    while(P--){
        char A, B;
        int a, b, w;
        scanf(" %c %c%d", &A, &B, &w);
        if(A - 'a' >= 0 && A - 'a' <= 25) a = A - 'a' + 1;
        if(A - 'A' >= 0 && A - 'A' <= 25) a = A - 'A' + 27;
        if(B - 'a' >= 0 && B - 'a' <= 25) b = B - 'a' + 1;
        if(B - 'A' >= 0 && B - 'A' <= 25) b = B - 'A' + 27;
        g[a][b] = g[b][a] = min(g[a][b], w);
    }

    dijkstra(52);

    int min = INF, t;
    for(int i = 27; i <= 51; i++)
        if(dist[i] < min){
            min = dist[i];
            t = i;
        }
    char T = t - 26 + 64;

    printf("%c %d", T, min);

    return 0;
}