求教：为什么只有40分

#include<cstdio>
#include<algorithm>
#include<cstring>
#define N 100005
using namespace std;
int n,m,q,ans,dist[N],in[N],son[N],vn[N*4];
struct edge{
    int ne,a,b,l;
} G[N*4],e[N*4];int num,v[N],ng,u[N];
inline void add(int a,int b){
    e[++num].a=a;e[num].b=b;
    e[num].ne=v[a]; v[a]=num;
}
inline void add2(int a,int b,int ng){
    G[ng].a=a;G[ng].b=b;
    G[ng].ne=u[a]; u[a]=ng;
}
void bfs(){
    bool visit[N];
    memset(visit,0,sizeof(visit));
    int queue[N],h=1,t=1;
    queue[1]=1;
    while(h<=t){
        int now=queue[h];
        for(int i=v[now];i;i=e[i].ne){
            int point=e[i].b;
            if(dist[point]>=dist[now]+1){
                add2(now,point,i); 
                son[(i+1)/2]=i;
                dist[point]=dist[now]+1;
                in[point]++;
                if(!visit[point]) queue[++t]=point;
                visit[point]=true;
            }
        }
        h++;
    }
}
inline void dfs(int now){
    //if(in[now]==0) return;
    in[now]--; if(!in[now]) {
        ans++;
        for(int i=u[now];i;i=G[i].ne){
            int point=G[i].b;
            if(in[point]&&!vn[i]) {vn[i]=1;dfs(point);}
        }
    }
}
int main(){
    scanf("%d%d%d",&n,&m,&q);in[1]=1;
    dist[1]=0; for(int i=2;i<=n;i++) dist[i]=N;
    for(int i=1;i<=m;i++){
        int a,b;
        scanf("%d%d",&a,&b);
        add(a,b); add(b,a);
    }
    bfs();
    for(int i=1;i<=q;i++){
        int r;
        scanf("%d",&r);if(son[r]==0){
            printf("%d\n",ans);
            continue;
        };
        if(G[son[r]].b) dfs(G[son[r]].b);
        vn[son[r]]=1;
        printf("%d\n",ans);
    }
    return 0;
}