HDOJ 2112（最短路）

#include<bits/stdc++.h>
#define x first
#define y second
#define PB push_back
#define mst(x,a) memset(x,a,sizeof(x))
#define all(a) begin(a),end(a)
#define rep(x,l,u) for(ll x=l;x<u;x++)
#define rrep(x,l,u) for(ll x=l;x>=u;x--)
#define IOS ios::sync_with_stdio(false);cin.tie(0);
using namespace std;
typedef unsigned long long ull;
typedef pair<int,int> PII;
typedef pair<long,long> PLL;
typedef pair<char,char> PCC;
typedef long long ll;
const int N=1e5+10;
const int M=1e6+10;
const int INF=0x3f3f3f3f;
const int MOD=1e9+7;
map<string,int> ID;
int e[N],ne[N],w[N],h[N],idx,dist[N],n;
bool st[N];
void add(int a,int b,int c){
    e[idx]=b,ne[idx]=h[a],w[idx]=c,h[a]=idx++;
}
int dijkstra(){
    mst(dist,INF);
    mst(st,false);
    priority_queue<PII,vector<PII>,greater<PII>> pq;
    pq.push({0,1});
    dist[1]=0;
    while(pq.size()){
        PII t=pq.top();pq.pop();
        int idx=t.y,distance=t.x;
        if(st[idx]) continue;
        st[idx]=true;
        for(int i=h[idx];i!=-1;i=ne[i]){
            int j=e[i];
            if(dist[j]>distance+w[i]){
                dist[j]=distance+w[i];
                pq.push({dist[j],j});
            }
        }
    }
    return dist[n]==INF ? -1 : dist[n];
}
void solve(){
    while(cin>>n){
        idx=0;
        if(n==-1) break;
        mst(h,-1);
        ID.clear();
        string st,ed;cin>>st>>ed;
        ID[st]=1,ID[ed]=n;
        int cnt=2;
        rep(i,0,n){
            string a,b;cin>>a>>b;
            int c;cin>>c;
            if(!ID[a]) ID[a]=cnt++;
            if(!ID[b]) ID[b]=cnt++;
            add(ID[a],ID[b],c);
            add(ID[b],ID[a],c);
        }
        if(st==ed){
            cout<<0<<endl;
            continue;
        }
        int t=dijkstra();
        cout<<t<<endl;
    }
}
int main(){
    IOS;
    solve();
    return 0;
}