[算法学习]优先队列优化的dijkstra算法求最短路

const int maxn = 1e4 + 5;
int n,m,s;
struct edge{
    int to,w;
};

struct node{
    int w,now;
    bool operator<(const node a) const {
        return w > a.w;
    }
};

int a,b,c;
vector<edge> mp[maxn]; //vector存边
int dis[maxn];                  
priority_queue<node> q; //优先队列对每个顶点进行处理
int f[maxn];    //标记当前顶点是否已经对其他点进行过更新操作

int main(){
    cin>>n>>m>>s;

    while(m--){
        scanf("%d%d%d", &a, &b, &c);
        mp[a].push_back(edge{b,c});
    }
    //读入边
    
    for(int i = 1; i <= n; i++)
        dis[i] = 0x3f3f3f3f;
    dis[s] = 0;
    //初始化dis数组

    q.push(node{0,s});
    while(!q.empty()){
        node x = q.top();
        q.pop();
        int u = x.now;
        if(f[u]) continue;
        f[u] = 1;
        for(int i = 0; i < mp[u].size(); i++){
            if(dis[mp[u][i].to] > dis[u] + mp[u][i].w){
                dis[mp[u][i].to] = dis[u] + mp[u][i].w;
                q.push(node{dis[mp[u][i].to], mp[u][i].to});
            }
        } //dijkstra核心代码
    }
    //优先队列处理

    for(int i = 1; i <= n; i++)
        cout<<dis[i]<<" ";
    return 0;
}