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| #include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<queue>
#define ll long long
#define INF 2147483647
using namespace std;
struct node{
int k,dis,used;
bool operator < ( const node &x )const{return x.dis < dis;}
};
priority_queue<node> que;
long long n,m,k,s,t,d[50005],cnt,D[50005][15],v[50005][15];
struct Edge{
int to,next,x;
}edge[2000005];
void add(int x,int y,int a)
{
edge[++cnt].to = y;
edge[cnt].x = a;
edge[cnt].next = d[x];
d[x] = cnt;
}
int main()
{
int x,y,a;
scanf("%lld%lld%lld",&n,&m,&k);
scanf("%d%d",&s,&t);
for(register int i = 1; i <= m; i++)
{
scanf("%d%d%d",&x,&y,&a);
add(x,y,a);
add(y,x,a);
}
que.push((node){s,0,0});
for(register int i = 0; i <= n; i++)
for(register int j = 0; j <= k; j++)
D[i][j] = INF;
D[s][0] = 0;
while(!que.empty())
{
node u = que.top();
que.pop();
int kk = u.k,level = u.used;
if(v[u.k][u.used]) continue;
v[u.k][u.used] = 1;
for(register int i = d[kk]; i; i = edge[i].next)
{
int too = edge[i].to;
if(D[too][level] > D[kk][level] + edge[i].x)
{
D[too][level] = edge[i].x + D[kk][level];
que.push((node){too,D[too][level],level});
}
if(level < k && D[too][level + 1] > D[kk][level])
{
D[too][level + 1] = D[kk][level];
que.push((node){too,D[too][level + 1],level + 1});
}
}
}
long long ans = INF;
for(register int i = 0; i <= k; i++) ans = min(ans,D[t][i]);
printf("%lld
",ans);
return 0;
}
|