Submission #647348

#	Time	Username	Problem	Language	Result	Execution time	Memory
647348		Karuk	Regions (IOI09_regions)	C++14	100 / 100	4999 ms	106688 KiB

regions

#include<bits/stdc++.h>
using namespace std;
const int bucket=450;
int parent[200001];
vector<int>children[200001];
int reg[200001];///regions
vector<int>indexx[25001];
vector<int>regions[25001];
int ticker=0;
int beg[200001],en[200001];
void dfs(int n) {
    indexx[reg[n]].push_back(ticker);
    beg[n]=ticker++;
    for(int i:children[n]) {
        dfs(i);
    }
    en[n]=ticker-1;
}
vector<int>large;
int num[25001];
map<pair<int,int>,int>ans;
void dfs1(int n) {
    for(int i:large) {
        ans[{i,reg[n]}]+=num[i];
    }
    num[reg[n]]++;
    for(int i:children[n]) {
        dfs1(i);
    }
    num[reg[n]]--;

}
int main() {
    int n,r,q;cin>>n>>r>>q;
    cin>>reg[1];
    regions[reg[1]].push_back(1);
    for(int i=2;i<=n;i++) {
        cin>>parent[i]>>reg[i];
        children[parent[i]].push_back(i);
        regions[reg[i]].push_back(i);
    }
    dfs(1);
    for(int i=1;i<=r;i++) {
        if(indexx[i].size()>=bucket)large.push_back(i);
    }
    dfs1(1);
    for(int i=0;i<q;i++) {
        int x,y;cin>>x>>y;
        if(indexx[x].size()>=bucket)cout<<ans[{x,y}]<<endl;
        else {
            int anss=0;
            for(int ind:regions[x]) {
                int pos1=upper_bound(indexx[y].begin(),indexx[y].end(),beg[ind])-indexx[y].begin();
                int pos2=upper_bound(indexx[y].begin(),indexx[y].end(),en[ind])-indexx[y].begin();
                anss+=pos2-pos1;

            }
            cout<<anss<<endl;
        }
    }
    return 0;
}

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