堆优化了一下

#include<bits/stdc++.h>
#define x first
#define y second
using namespace std;

struct edge{
    int to,cost;
};
int const N=10010;
typedef pair<int,int> P;//x是距离，y是编号
vector<edge> a[N];
priority_queue<P,vector<P>,greater<P> > q;
int n,dis[N];

int get(char a){
    return int(a);
}

void dijk(){
    memset(dis,0x3f,sizeof dis);
    dis[get('Z')]=0;
    q.push({0,get('Z')});
    while(!q.empty()){
        auto e=q.top();q.pop();
        int from=e.y;//当前点
        if(dis[from]<e.x)continue;
        for(int i=0;i<a[from].size();i++){
            auto e=a[from][i];//下一个点
            if(dis[e.to]>dis[from]+e.cost){
                dis[e.to]=dis[from]+e.cost;
                q.push({dis[e.to],e.to});
            }
        }
    }
}

int main(){
    //ios::sync_with_stdio(false);
    cin.tie(0);
    cin>>n;
    for(int i=0;i<n;i++){
        char from,to;
        int w;cin>>from>>to>>w;
        int u=get(from),v=get(to);
        //printf("%d %d %d\n",u,v,w);
        a[u].push_back({v,w});
        a[v].push_back({u,w});
    }
    dijk();
    int ans1=0x3f3f3f3f,ans2;
    for(int i='A';i<='Z';i++)
        //cout<<char(i)<<" "<<dis[i]<<endl;
    for(int i='A';i<int('Z');i++){
        if(ans1>dis[i]){
            ans1=dis[i];
            ans2=i;
        }
    }
    cout<<char(ans2)<<" "<<ans1<<endl;
    return 0;
}
//注意数据范围!小心爆int
//注意边界问题
//注意特殊情况！！！！！