用户:Chenjunyi.horse

这个人很懒，什么也没留下。。。。。

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <queue>
using namespace std;

const int maxn = 500000 + 100;

struct edge {
	int v, w, next;
	edge(int v=0, int w=0, int next=0) : v(v), w(w), next(next) {
		v=v; w=w; next=next;
	}
}e[maxn];
int front[maxn], tot=0;

int Addedge(int u, int v, int w) {
	tot++;
	e[tot].v = v;
	e[tot].w = w;
	e[tot].next = front[u];
	front[u] = tot;
}

int N, M, S;

void Readin() {
	ios::sync_with_stdio(false);
	cin >> N >> M >> S;
	for(int i = 1; i <= M; i++) {
		int u, v, w;
		cin >> u >> v >> w;
		Addedge(u, v, w);
	}
}

struct Heap {
	int id, w;
	bool operator < (const Heap &rhs) const {
		return w < rhs.w;
	}
};

int dis[maxn];
int Dijkstra(int s) {
	priority_queue<Heap> q;
	for(int i = 1; i <= N; i++) dis[i] = 2147483647;
	dis[s] = 0;
	q.push(Heap{s, dis[s]});
	while(!q.empty()) {
		Heap x = q.top(); q.pop();
		if(dis[x.id] != x.w) continue;
		for(int i = front[x.id]; i != 0; i = e[i].next) {
			int k = e[i].v;
			if(dis[k] > dis[x.id] + e[i].w) {
				dis[k] = dis[x.id] + e[i].w;
				q.push(Heap{k, dis[k]});
			}
		}
	}
	for(int i =  1; i <= N; i++) cout << dis[i] << ' ';
	cout << endl;
	return 0;
}

int SPFA(int s) {
	queue<int> q;
	bool inq[maxn] = {false};
	for(int i = 1; i <= N; i++) dis[i] = 2147483647;
	dis[s] = 0;
	q.push(s); inq[s] = true;
	while(!q.empty()) {
		int x = q.front(); q.pop();
		inq[x] = false;
		for(int i = front[x]; i !=0 ; i = e[i].next) {
			int k = e[i].v;
			if(dis[k] > dis[x] + e[i].w) {
				dis[k] = dis[x] + e[i].w;
				if(!inq[k]) {
					inq[k] = true;
					q.push(k);
				}
			}
		}
	}
	for(int i =  1; i <= N; i++) cout << dis[i] << ' ';
	cout << endl;
	return 0;
}

int main() {
	Readin();
	SPFA(S);
	return 0;
}