Codeforces_739_B

http://codeforces.com/problemset/problem/739/B

dfs，记录距离前缀和，每次找到离最近的不符合的点。

#include<iostream>
#include<cstring>
#include<cstdio>
#include<algorithm>
#include<vector>
using namespace std;
 
int n,cnt = ,a[],b[],sta[],ans[] = {};
long long dis[];
vector<int> v[];
 
void dfs(int x,long long deep)
{
    sta[++cnt] = x;
    dis[x] = deep;
    for(int i = ;i < v[x].size();i++)
    {
        int t = v[x][i];
        dfs(t,dis[x]+b[t]);
        ans[x] += ans[t]+;
    }
    int l = ,r = cnt-;
    while(l < r)
    {
        int mid = (l+r+)/;
        if(dis[x]-dis[sta[mid]] > a[x]) l = mid;
        else    r = mid-;
    }
    ans[sta[l]]--;
    cnt--;
}
int main()
{
    scanf("%d",&n);
    for(int i = ;i <= n;i++)   scanf("%d",&a[i]);
    for(int i = ;i <= n;i++)
    {
        int x,y;
        scanf("%d%d",&x,&y);
        v[x].push_back(i);
        b[i] = y;
    }
    dfs(,);
    for(int i = ;i <= n;i++)   printf("%d ",ans[i]);
    printf("\n");
    return ;
}