codevs 1835 魔法猪学院 A*寻k短路做了一个月卡死在spfa那了/(ㄒoㄒ)/~~

#include<queue>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int point[5003],next[200003],v[200003],point2[5003],next2[200003],v2[200003],cnt=0,cnt2=0,N,M;
double c[200003],c2[200003],dist[5003],E;
bool p[5003];
struct datatype{
    double g; int isk;
    bool operator < (const datatype &a) const
    {
        return g+dist[isk]>a.g+dist[a.isk];
    }
};
void insect(int x,int y,double z){next[cnt]=point[x];point[x]=cnt;v[cnt]=y;c[cnt]=z;cnt++;}
void insect2(int x,int y,double z){next2[cnt2]=point2[x];point2[x]=cnt2;v2[cnt2]=y;c2[cnt2]=z;cnt2++;}
void SPFA()
{
    p[N]=1; queue<int>Q;Q.push(N); dist[N]=0.0; int i,now;
    while (!Q.empty())
    {
        now=Q.front(); Q.pop(); p[now]=0;
        for (i=point2[now];i!=-1;i=next2[i])
         if (dist[v2[i]]>dist[now]+c2[i])
          {dist[v2[i]]=dist[now]+c2[i];if (p[v2[i]]==0){p[v2[i]]=1;Q.push(v2[i]);}}
    }
}
void Astar()
{
    priority_queue<datatype>q; cnt=0;
    int i,now; double nowg; datatype A; A.g=0.0; A.isk=1; q.push(A);
    while ((E>0)&&(!q.empty()))
    {
        now=q.top().isk; nowg=q.top().g; q.pop();
        if (now==N)
         {E=E-nowg; if (E>=0) {cnt++;continue;} else break;}
        for (i=point[now];i!=-1;i=next[i])
         {A.isk=v[i];A.g=nowg+c[i];q.push(A);}
    }printf("%d\n",cnt);
}
int main()
{
    memset(point,-1,sizeof(point));
    memset(point2,-1,sizeof(point2));
    memset(next,-1,sizeof(next));
    memset(next2,-1,sizeof(next2));
    memset(v,0,sizeof(v));
    memset(v2,0,sizeof(v2));
    memset(c,0,sizeof(c));
    memset(c2,0,sizeof(c2));
    memset(dist,0x43,sizeof(dist));
    memset(p,0,sizeof(p));
    scanf("%d %d %lf\n",&N,&M,&E);
    int i,x,y; double z;
    for (i=1;i<=M;++i)
    {
        scanf("%d %d %lf\n",&x,&y,&z);
        insect(x,y,z);
        insect2(y,x,z);
    }SPFA();
    Astar();
    return 0;
}