ACM-ICPC2018 沈阳赛区网络预赛-D-Made In Heaven8

#include <bits/stdc++.h>
using namespace std;
const int N=1005;
const int M=100005;
inline int read()
{
    int x=0,f=1;char ch=getchar();
    while (ch<‘0‘ || ch>‘9‘){if (ch==‘-‘) f=-1;ch=getchar();}
    while (ch>=‘0‘ && ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}
    return x*f;
}
int n,m,sta,en,kth,T,Ecnt,Eoppcnt;
int dist[N];
int times[N];
bool vis[N];
struct Edge{
    int to,next,val;}E[M],Eopp[M];//Eopp means Eopposite
int last[N],last_opp[N];
struct A_Star_node{
    int p,g,h;
    bool operator < (A_Star_node x)const
    {
        return x.g+x.h<g+h;
    }
};//means point  and a_Star:f(x)=g(x)+h(x);
priority_queue<A_Star_node>Q;
inline void add(int u,int v,int w)
{
    Ecnt++;
    E[Ecnt].next=last[u];
    E[Ecnt].to=v;
    E[Ecnt].val=w;
    last[u]=Ecnt;
}
inline void add_opposite(int u,int v,int w)
{
    Eoppcnt++;
    Eopp[Eoppcnt].next=last_opp[u];
    Eopp[Eoppcnt].to=v;
    Eopp[Eoppcnt].val=w;
    last_opp[u]=Eoppcnt;
}
void dij(int s,int e)
{
    memset(vis,0,sizeof(vis));
    memset(dist,127,sizeof(dist));
    int mi;
    dist[e]=0;
    for (int i=1;i<=n;i++)
    {
        mi=0;
        for (int j=1;j<=n;j++)
            if (!vis[j] && dist[mi]>dist[j])    mi=j;
        vis[mi]=1;
        for (int x=last_opp[mi];x;x=Eopp[x].next)
            dist[Eopp[x].to]=min(dist[Eopp[x].to],dist[mi]+Eopp[x].val);
    }
}
int A_Star(int s,int e)
{
    A_Star_node t1,tmp;
    memset(times,0,sizeof(times));
    while (!Q.empty()) Q.pop();
    t1.g=t1.h=0; t1.p=s;
    Q.push(t1);
    while (!Q.empty())
    {
        t1=Q.top();    Q.pop();
        times[t1.p]++;
        if (times[t1.p]<=kth && t1.h>T) return -1;//K短路之前的路已经比要求的时间长了，一定是不合法的方案
        if (times[t1.p]==kth && t1.p==e) return t1.h;
        if (times[t1.p]>kth) continue;
        for (int i=last[t1.p];i;i=E[i].next)
        {
            tmp.p=E[i].to;
            tmp.g=dist[E[i].to];
            tmp.h=E[i].val+t1.h;
            Q.push(tmp);
        }
    }
    return -1;
}
int main()
{
    while (scanf("%d%d",&n,&m)!=EOF)
    {
        sta=read(); en=read(); kth=read(); T=read();
        int x,y,z;
        memset(last,0,sizeof(last));
        memset(last_opp,0,sizeof(last_opp));
        Ecnt=0;
        Eoppcnt=0;
        while (m--)
        {
            x=read(); y=read(); z=read();
            add(x,y,z);
            add_opposite(y,x,z);
        }
        dij(sta,en);
        if (sta==en) kth++;
        int ans=A_Star(sta,en);
        if (ans==-1||ans>T) puts("Whitesnake!");
        else puts("yareyaredawa");
    }
    return 0;
}