bzoj2763: [JLOI2011]飞行路线

#include<cstdio>
#include<cstring>
#include<cctype>
#include<algorithm>
#include<queue>
using namespace std;
#define rep(i,s,t) for(int i=s;i<=t;i++)
#define dwn(i,s,t) for(int i=s;i>=t;i--)
#define clr(x,c) memset(x,c,sizeof(x))
#define qwq(x) for(edge *o=head[x];o;o=o->next)
int read(){
    int x=0;char c=getchar();
    while(!isdigit(c)) c=getchar();
    while(isdigit(c)) x=x*10+c-‘0‘,c=getchar();
    return x;
}
const int nmax=1e4+5;
const int maxn=1e5+5;
const int inf=0x7f7f7f7f;
struct edge{
    int to,dist;edge *next;
};
edge es[maxn],*pt=es,*head[nmax];
void add(int u,int v,int d){
    pt->to=v;pt->dist=d;pt->next=head[u];head[u]=pt++;
    pt->to=u;pt->dist=d;pt->next=head[v];head[v]=pt++;
}
int dist[nmax][11];
struct node{
    int x,k,dist;
    node(int x,int k,int dist):x(x),k(k),dist(dist){};
    node(){};
    bool operator<(const node&rhs)const{
      return dist>rhs.dist;}
};
priority_queue<node>q;
void dijkstra(int s,int t,int k){
    clr(dist,0x7f);dist[s][0]=0;q.push(node(s,0,0));
    node o;int ta,td,tk,to;
    while(!q.empty()){
        o=q.top();q.pop();ta=o.x,td=o.dist,tk=o.k;
        if(dist[ta][tk]!=td) continue;
        qwq(ta){
            to=o->to;
            if(dist[o->to][tk]>td+o->dist){
                dist[o->to][tk]=td+o->dist;q.push(node(o->to,tk,td+o->dist));
            }
            if(tk<k&&dist[o->to][tk+1]>td){
                dist[o->to][tk+1]=td;q.push(node(o->to,tk+1,td));
            }
        }
    }
    int ans=inf;
    rep(i,0,k) ans=min(ans,dist[t][i]);
    printf("%d\n",ans);
    return ;
}
int main(){
    int n=read(),m=read(),k=read(),u,v,d,s=read(),t=read();
    rep(i,1,m) u=read(),v=read(),d=read(),add(u,v,d);
    dijkstra(s,t,k);
    return 0;
}