[patl2-020]功夫传人

解题关键：dfs的简单应用，需要注意类型double与int

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cstdlib>
#include<iostream>
#include<cmath>
#define maxn 100002
using namespace std;
typedef long long ll;
int n;
double z,r;
int vis[maxn];
int cnt=,head[maxn];
struct edge{
    int to,nxt;
}e[maxn];
void add_edge(int u,int v){
    e[cnt].to=v;
    e[cnt].nxt=head[u];
    head[u]=cnt++;
}

double dfs(int u,double val){
    if(vis[u]){
        val*=vis[u];
        return val;
    }
    double res=;
    val*=r;
    for(int i=head[u];i!=-;i=e[i].nxt){
        int v=e[i].to;
        res+=dfs(v,val);
    }
    return res;
}

int main(){
    memset(head, -, sizeof head);
    cin>>n>>z>>r;
    r=-0.01*r;
    for(int i=;i<n;i++){
        int tmp,t2;
        cin>>tmp;
        if(tmp==){
            cin>>t2;
            vis[i]=t2;
        }else{
            for(int j=;j<tmp;j++){
                int t;
                cin>>t;
                add_edge(i,t);
            }
        }
    }
    printf("%d\n",(int)dfs(,z));
    return ;
}