```cpp
#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
#define E 1000010
#define inf 1e11
#define ll long long
using namespace std;
int n,m,k;
int s,t,u,v;
ll w;
struct node{
int to;
int next;
ll value;
}edge[E];
int head[E];
ll dis[E];
bool vis[E];
int cnt;
void add_edge(int u,int v,ll w)
{
cnt++;
edge[cnt].to=v;
edge[cnt].next=head[u];
head[u]=cnt;
edge[cnt].value=w;
}
void dijkstra(int x)
{
priority_queue<pair<ll,int> > q;
for(int i=0;i<=(k+1)*n+2;i++)
{
dis[i]=inf;
vis[i]=false;
}
dis[x]=0;
q.push(make_pair(0,x));
while(!q.empty())
{
int temp=q.top().second;
q.pop();
if(vis[temp])continue;
vis[temp]=true;
for(int i=head[temp];i;i=edge[i].next)
{
if(dis[temp]+edge[i].value<dis[edge[i].to])
{
dis[edge[i].to]=dis[temp]+edge[i].value;
q.push(make_pair(-dis[edge[i].to],edge[i].to));
}
}
}
}
int main()
{
scanf("%d%d%d%d%d",&n,&m,&k,&s,&t);
s++,t++;
for(int i=1;i<=m;i++)
{
scanf("%d%d%lld",&u,&v,&w);
u++,v++;
for(int j=0;j<=k;j++)
{
add_edge(u+j*n,v+j*n,w);
add_edge(v+j*n,u+j*n,w);
}
if(k)for(int j=0;j<=k-1;j++)
{
add_edge(u+j*n,v+(j+1)*n,0);
add_edge(v+j*n,u+(j+1)*n,0);
}
}
add_edge((k+1)*n+1,s,0);
for(int i=0;i<=k;i++)add_edge(t+i*n,(k+1)*n+2,0);
dijkstra((k+1)*n+1);
printf("%lld\n",dis[(k+1)*n+2]);
return 0;
}
```
by Zed_ @ 2019-04-01 00:20:34
orz！！！
by A_Big_Jiong @ 2019-04-01 00:29:43
@[Zed_](/space/show?uid=73092) ~~怎么什么题都能评上紫~~你这是加边加炸了...题目的$m<=50000,k<=10$，双向边开双倍，再乘上$k$是$1e6$，但是你的代码里有一段不明所以的
```cpp
add_edge((k+1)*n+1,s,0);
for(int i=0;i<=k;i++)add_edge(t+i*n,(k+1)*n+2,0);
```
所以很明显空间起码比$1e6$多开$k*2$的大小...不懂你的思路...
by ZPC2048 @ 2019-04-01 01:16:57
@[Zed_](/space/show?uid=73092)
链式前向星开到1e7A了
by Smile_Cindy @ 2019-04-01 10:03:33
好的，明白了，谢谢
by Zed_ @ 2019-04-01 12:10:32