Submission #1244295

#	Time	Username	Problem	Language	Result	Execution time	Memory
1244295		whtth	Regions (IOI09_regions)	C++20	100 / 100	2711 ms	30428 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], block=447;
vector<int> ke[200010];
vector<int> f[25001];
vector<int> g[25001];
vector<int> hev[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;
}
void dfs2(int u, int p, int sum, int target){
    if(qg[u]==target)sum++;
    hev[x][qg[u]]+=sum;
    for(int v : ke[u]){
        if(v==p)continue;
        dfs2(v, u, sum, target);
    }
}
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++){
        cin>>x>>y;
        if(g[x].size()<=block){
            int ans=0;
            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<<endl;
        }
        else {
            if(hev[x].empty()){
                hev[x].resize(r+1, 0);
                dfs2(1, 0, 0, x);
            }
            cout<<hev[x][y]<<endl;
        }
    }
    return 0;
}

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