蒟蒻求调
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蒟蒻求调
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luogu_MeiFengqi楼主2024/7/17 15:41

刚学dijkstra,不知道如何存路径,大佬们可否指导一二

#include<bits/stdc++.h>
using namespace std;
#define maxn INT_MAX
#define int long long int
int head[100005],vis[100005],cnt;
int dis[100005];
struct edge{
	int to,next,val;
}e[500005];
struct node{
	int v,dis;
	bool operator < (const node &b)const{
		return dis>b.dis;
	}
};
int read()
{
	int x=0;
	char ch=getchar();
	while(ch>57||ch<48) ch=getchar();
	while(ch>=48&&ch<=57)
	{
		x=x*10+ch-'0';
		ch=getchar();
	}
	return x;
}
void add(int u,int v,int w)
{
	e[++cnt].to=v;
	e[cnt].next=head[u];
	e[cnt].val=w;
	head[u]=cnt;
}
int n,m,s,u,v,w;
priority_queue<node> q;
void dj(){
	q.push({s,0});
	while(!q.empty()){
		node cur=q.top();
		q.pop();
		if(vis[cur.v]) continue;
		vis[cur.v]=1;
		for(int i=head[cur.v];i;i=e[i].next)
		{
			if(dis[e[i].to]>dis[cur.v]+e[i].val)
			{
				dis[e[i].to]=dis[cur.v]+e[i].val;
				q.push({e[i].to,dis[e[i].to]});
			}
		}
	}
}
signed main()
{
	n=read();m=read();s=read();
	for(int i=1;i<=n;i++) dis[i]=maxn;
	dis[s]=0;
	for(int i=1;i<=m;i++)
	{
		u=read();v=read();w=read();
		add(u,v,w);
	}
	dj();
	for(int i=1;i<=n;i++) printf("%lld ",dis[i]);
	return 0;
}
2024/7/17 15:41
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