样例爆零求条

#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll n,m,k,s,t;
struct edge{
	ll v,w;
};vector<edge> G[50010];
struct node{
	ll u,dis;
	friend bool operator <(node x,node y){
		return x.dis>y.dis;
	} 
};priority_queue<node> q;
ll dis[10010],vis[10010];
void dijkstra(){
	for(int i=1;i<=n;i++) dis[i]=1e18;
	dis[s]=0;
	q.push({s,0});
	while(!q.empty()){
		node op=q.top();
		q.pop();
		ll u=op.u;
		
		if(vis[u]) continue;
		vis[u]=1;
		
		for(int i=0;i<G[u].size();i++){
			ll v=G[u][i].v,w=G[u][i].w;
			if(dis[v]>dis[u]+w){
				dis[v]=dis[u]+w;
				q.push({v,dis[v]}); 
			}
		} 
	}
} 
int main(){
	cin>>n>>m>>k>>s>>t;
	for(int i=1;i<=m;i++){
		int u,v,w;
		cin>>u>>v>>w;
		G[u].push_back({u,w});
		G[v].push_back({v,w});
		for(int j=1;j<=k;j++){
			G[u+j*n].push_back({v+j*n,w});
			G[v+j*n].push_back({u+j*n,w});
			G[u+(j-1)*n].push_back({v+j*n,0});
			G[v+(j-1)*n].push_back({u+j*n,0});
		}
	}
	for(int i=1;i<=k;i++) G[t+(i-1)*n].push_back({t+i*n,0});
	dijkstra();
	cout<<dis[t+n*k];
	return 0;
}