单源最短路狄克斯特拉 + 链式前向星 + 堆 优化

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#include<bits/stdc++.h>
#include<queue>
using namespace std;
const int maxn = 1e6;
const int INF = (1<<31 -1);
int head[maxn],dis[maxn],vis[maxn],n,m,s,cnt;
priority_queue<pair<int,int>,vector<pair<int,int> >,greater<pair<int,int> > >q;//优先队列的写法stl中的结构体pair
//链式前向星存储图
struct node
{
	int to,w,next;
}e[maxn]; 

void add(int u, int v, int w)
{
	e[++cnt].w = w;
	e[cnt].to = v;
	e[cnt].next = head[u];
	head[u] = cnt;
}

void dijkstra()
{
	int i;
	for(i = 1; i<=n; i++)
		dis[i] = INF;
	dis[s] = 0;
	q.push(make_pair(0,s));
	while(!q.empty())
	{
		int t = q.top().second; 
		q.pop();
		if(vis[t]==1) continue;
		vis[t] = 1;
		for( i = head[t]; i; i = e[i].next )
		{
			if(dis[e[i].to] > dis[t] + e[i].w)
			{
				dis[e[i].to] = dis[t] + e[i].w;
				q.push(make_pair(dis[e[i].to],e[i].to));
			}
		}
		
	} 
}
int main()
{
	int u,v,w;
	cin>>n>>m>>s;
	for(int i=0; i<m; i++)
	{
		cin>>u>>v>>w;
		add(u,v,w);
	}
	dijkstra();
	for(int i = 1; i<=n; i++)
	{
		if(i!=1) cout<<" ";
		cout<<dis[i];
	}
	cout<<endl;
	return 0;
} 

标签：cnt,狄克,cin,int,单源,next,head,前向星,dis
来源： https://blog.csdn.net/Wuko666/article/details/112547067