【模板】单源最短路径spfa

P3371 【模板】单源最短路径

发现自己的博客居然没有spfa？？这样是不完整的!!(雾

贴板子qwq

#include<queue>
#include<cstdio>
#include<iostream>
using namespace std;
const int maxn = 10010, maxm = 500050, inf = 2147483647;
int n, m, s, num = 0;
int head[maxm], dis[maxn];
bool vis[maxn];
struct edge {
    int nxt, to, dis;
}e[maxm];
void add(int from, int to, int dis) {
    e[++num].nxt = head[from];
    e[num].to = to;
    e[num].dis = dis;
    head[from] = num;
}
void spfa() {
    queue<int>q;
    for(int i = 1; i <= n; i++) {
        dis[i] = inf;
        vis[i] = 0;
    }
    q.push(s);
    dis[s] = 0;
    vis[s] = 1;
    while(!q.empty()) {
        int u = q.front();
        q.pop();
        vis[u] = 0;//日常忘记打这一句QAQ
        for(int i = head[u]; i; i = e[i].nxt) {
            int v = e[i].to;
            if(dis[v] >= dis[u]+e[i].dis) {
                dis[v] = dis[u]+e[i].dis;
                if(!vis[v]) {
                    vis[v] = 1;
                    q.push(v);
                }
            }
        }
    }
}
int main() {
    scanf("%d%d%d", &n, &m, &s);
    for(int i = 1; i <= m; i++) {
        int f, g, k;
        scanf("%d%d%d", &f, &g, &k);
        add(f, g, k);
    }
    spfa();
    for(int i = 1; i <= n; i++) 
        printf("%d ", dis[i]);
    return 0;
}

觉得自己码风超棒哈哈哈哈哈哈哈

但博客中代码字体丑的一比QAQ还不会改QAQ

10/17 今天日常敲板子， wa的我一脸懵逼， 发现我建了双向边orz