1 #include<cstdio> 2 #include<cstring> 3 #include<iostream> 4 #include<queue> 5 #define pa pair<int,int> 6 #define inf 0x7fffffff 7 #define M 400008 8 using namespace std; 9 int d[M],f[M],n,m,k,s,t,cnt,head[M],next[10*M],u[10*M],v[10*M]; 10 void jia(int a1,int a2,int a3) 11 { 12 cnt++; 13 next[cnt]=head[a1]; 14 head[a1]=cnt; 15 u[cnt]=a2; 16 v[cnt]=a3; 17 return; 18 } 19 int main() 20 { 21 scanf("%d%d%d",&n,&m,&k); 22 scanf("%d%d",&s,&t); 23 for(int i=1;i<=m;i++) 24 { 25 int a1,a2,a3; 26 scanf("%d%d%d",&a1,&a2,&a3); 27 jia(a1,a2,a3); 28 jia(a2,a1,a3); 29 for(int j=1;j<=k;j++) 30 { 31 jia(j*n+a1,j*n+a2,a3); 32 jia(j*n+a2,j*n+a1,a3); 33 jia((j-1)*n+a1,j*n+a2,0); 34 jia((j-1)*n+a2,j*n+a1,0); 35 } 36 } 37 priority_queue<pa,vector<pa>,greater<pa> >q; 38 memset(d,60,sizeof(d)); 39 q.push(make_pair(0,s)); 40 d[s]=0; 41 for(;!q.empty();) 42 { 43 int now=q.top().second; 44 q.pop(); 45 if(f[now]) 46 continue; 47 f[now]=1; 48 for(int i=head[now];i;i=next[i]) 49 if(d[u[i]]>d[now]+v[i]) 50 { 51 d[u[i]]=d[now]+v[i]; 52 q.push(make_pair(d[u[i]],u[i])); 53 } 54 } 55 int ans=inf; 56 for(int i=0;i<=k;i++) 57 ans=min(ans,d[i*n+t]); 58 printf("%d\n",ans); 59 return 0; 60 }
分层图按k分层
