[算法学习]Bellman-Ford算法求最短路

#include<bits/stdc++.h>
using namespace std;

//Bellman-Ford 队列优化
const int maxn = 1e5 + 5;

struct edge{
    int to,w;
};

bool book[maxn];
int dis[maxn];
queue<int> q;
vector<edge> edges[maxn];
int n,m,s;
int u,v,w;

int main(){
    cin>>n>>m>>s;
    while(m--){
        scanf("%d%d%d", &u, &v, &w);
        edges[u].push_back(edge{v,w});
    }
    fill(dis,dis+n+1,0x3f3f3f3f);
    dis[s] = 0;

    book[s] = 1;
    q.push(s);
    while(!q.empty()){
        int t = q.front();
        
        q.pop();
        for(int i = 0; i < edges[t].size(); i++){
            if(dis[edges[t][i].to] > dis[t] + edges[t][i].w){
                dis[edges[t][i].to] = dis[t] + edges[t][i].w;
                if(!book[edges[t][i].to]){
                    book[edges[t][i].to] = 1;
                    q.push(edges[t][i].to);
                }
            }
        }
        book[t] = 0;
    }

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