P4779 【模板】单源最短路径(堆优化dijkstra)

堆优化dijkstra，时间复杂度，我个人写习惯的模版。

#include
using namespace std;
#define PII pair
#define fi first
#define se second
const int N=2e5+10;

int read(){
	int x=0,f=1;char ch=getchar();
	while(!isdigit(ch)){
		if(ch=='-') f=-1;
		ch=getchar();
	}
	while(isdigit(ch)) x=x*10+ch-'0',ch=getchar();
	return x*f;
}

int n,m,s,head[N],tot,dist[N],vis[N];
priority_queue,greater > q;

struct node{
	int to,nxt,w;
}edge[N];
void add(int x,int y,int w){
	edge[++tot].to=y;
	edge[tot].w=w;
	edge[tot].nxt=head[x];
	head[x]=tot;
}

void dijkstra(int s){
	memset(dist,0x3f,sizeof(dist)),memset(vis,0,sizeof(vis));
	q.push(make_pair(0,s)),dist[s]=0;
	while(!q.empty()){
		int t=q.top().se;q.pop();
		if(vis[t]) continue;
		vis[t]=1;
		for(int i=head[t];i;i=edge[i].nxt){
			int y=edge[i].to;
			if(dist[y]>dist[t]+edge[i].w){
				dist[y]=dist[t]+edge[i].w;
				q.push(make_pair(dist[y],y));
			}
		}
	}
}

int main(){
	
	n=read(),m=read(),s=read();
	for(int i=1;i<=m;i++){
		int x=read(),y=read(),w=read();
		add(x,y,w);
	}
	dijkstra(s);
	for(int i=1;i<=n;i++) cout<