Djiskra + 鄰接表存圖 + 優先隊列優化

測試板子：https://www.luogu.org/problemnew/show/P3371

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
#include<string>
#include<vector>
#include<stack>
#include<bitset>
#include<cstdlib>
#include<cmath>
#include<set>
#include<list>
#include<deque>
#include<map>
#include<queue>
using namespace std;
typedef long long ll;
const double PI = acos(-1.0);
const double eps = 1e-6;
const int INF = 0x3f3f3f3f;
const int maxn = 1e6+10;
int dis[maxn];
int n,m,s;
typedef pair<int,int> P;
vector<P> E[maxn]; //鄰接表寸土

void Djiskra(){
    memset(dis,INF,sizeof(dis));
    dis[s] = 0;
    priority_queue<P> que;  //優先隊列優化
    que.push(P(0,s));  //這裏的第一個數代表 後面的數到起點的距離
    while(!que.empty()){
        P p = que.top(); que.pop();
        int v = p.second;  //獲取距離最短的點
        for(int i = 0;i < E[v].size();i++){  //鄰接表遍歷
            P e = E[v][i];
            if(dis[e.first] > dis[v] + e.second){
                dis[e.first] = dis[v] + e.second;
                que.push(P(-dis[e.first],e.first));  //這裏由於優先隊列默認由大到小排列，所以我存負數就可以由小到大
            }
        }
    }

    for(int i = 1;i <= n;i++)
        if(dis[i] == INF)
            cout << "2147483647" << " ";
        else
            cout << dis[i] << " ";
    cout << endl;
}

int main(){
    while(cin >> n >> m >> s){
        int x,y,z;
        for(int i = 0;i < m;i++){
            cin >> x >> y >> z;
            E[x].push_back(P(y,z));
        }
       Djiskra();
    }
    return 0;
}