Submission #1244260

#	Time	Username	Problem	Language	Result	Execution time	Memory
1244260		whtth	Regions (IOI09_regions)	C++20	0 / 100	62 ms	29472 KiB

regions

#include<bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
int n, m, r, k, ans=0, x, y, z, st[200010], en[200010], timer=0, qg[200010];
vector<int> ke[200010];
vector<int> f[25001];
vector<int> g[25001];
void dfs(int u, int t){
    st[u]=++timer;
    f[qg[u]].push_back(st[u]);
    g[qg[u]].push_back(u);
    for(int v : ke[u]){
        if(v!=t){
            dfs(v, u);
        }
    }
    en[u]=timer;
}
bool cmp(int a, int b){
    return st[a]<st[b];
}
int main(){
    ios::sync_with_stdio(0);cin.tie(nullptr);
    cin>>n>>r>>m;
    for(int i=1;i<=n;i++){
        int x, y;
        if(i!=1){
            cin>>x;
            ke[x].push_back(i);
        }
        cin>>qg[i];
    }
    dfs(1, 0);
    for(int i=1;i<=m;i++){
        int x, y, ans=0;
        cin>>x>>y;
        for(int u : g[x]){
            auto itL = lower_bound(f[y].begin(), f[y].end(), st[u]);
            auto itR = upper_bound(f[y].begin(), f[y].end(), en[u]);
            ans += (itR - itL);
        }
        cout<<ans<<"\n";
    }
    return 0;
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 85