Dijkstra模板题求调，悬赏1关

//2023/5/4
//别着急，先通读一遍题目
//别忘了开long long
//写完先看一遍怎么降复杂度
//要么开全局变量要么给定初值
//想想看，有什么情况需要特判
//std::ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
#include<bits/stdc++.h>
using namespace std;
const int MAXN=1e6+10;
const int INF=0x3f3f3f3f;
int num,ans,s,t,n,m;
struct node{
	int id;
	double dist;
	node()
	{
		id=0;dist=0;
	}
	node(int c,int d)
	{
		id=c;dist=d;
	}
};
auto cmp=[](node x,node y)->bool{return x.dist<y.dist;};
priority_queue<node,vector<node>,decltype(cmp)> que(cmp);
struct point{
	int x,y;
}a[1100];
struct linkstar{
	int to,from;
	double w;
	int next;
}edge[1100];

int head[1100];
double dis[1100];
bool vis[1100];
int escnt;
void add(int from,int to)
{
	edge[++escnt].from=from;
	edge[escnt].to=to;
	edge[escnt].w=sqrt(pow(double(a[from].x-a[to].x),2)+pow(double(a[from].y-a[to].y),2));
	edge[escnt].next=head[from];
	head[from]=escnt;
}
void Dijkstra(int u)
{
	for (int i=1;i<=n;i++)
	{
		dis[i]=INF;
	}
	dis[u]=0;
	que.push(node(u,0));
	int cnt=0;
	while(cnt<n)
	{
		node cp=que.top();
		que.pop();
		cnt++; 
		if(vis[cp.id]) continue;
		vis[cp.id]=true;
		for (int i=head[cp.id];i!=-1;i=edge[i].next)
		{
			if(dis[edge[i].to]>dis[cp.id]+edge[i].w)
			{
				dis[edge[i].to]=dis[cp.id]+edge[i].w;
				que.push(node(edge[i].to,dis[edge[i].to]));
			}
		}
	}
}
int main()
{
	memset(head,-1,sizeof(head));
	cin>>n;
	for (int i=1;i<=n;i++)
	{
		cin>>a[i].x>>a[i].y;
	}
	cin>>m;
	for (int i=1;i<=m;i++)
	{
		int x,y;
		cin>>x>>y;
		add(x,y);
		add(y,x);
	}
	cin>>s>>t;
	Dijkstra(s);
	printf("%.2f",dis[t]);
	return 0;
}