제출 #53656

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
53656		Diuven	Regions (IOI09_regions)	C++11	100 / 100	6917 ms	44460 KiB

regions

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<int, bool> pib;
const int MX=200010, inf=2e9;

void out(int x){
    cout<<x<<'\n'<<flush;
}
vector<int> P[25010]; // dfs indexes
vector<pib> Q[25010];
vector<int> G[MX];
int n, H[MX], q, r;

int num[MX], sub[MX], now;

void dfs(int v){
    num[v]=++now;
    sub[num[v]]=num[v];
    for(int x:G[v]){
        dfs(x);
        sub[num[v]]=max(sub[num[v]], sub[num[x]]);
    }
}

void init(){
    dfs(1);
    for(int i=1; i<=n; i++){
        int x=num[i], y=sub[x];
        P[H[i]].push_back(x);
        Q[H[i]].push_back({x,0});
        Q[H[i]].push_back({y,1});
    }
    for(int i=1; i<=r; i++){
        sort(P[i].begin(), P[i].end());
        sort(Q[i].begin(), Q[i].end());
    }
}

unordered_map<ll, int> D;
unordered_map<ll, bool> done;
// 1(st), 2(pt), 3(ed)

int solve(int x, int y){
    ll idx=((ll)x<<30)+y;
    if(done[idx]) return D[idx];
    int &ans=D[idx]; ans=0; done[idx]=true;
    int cnt=0;

    int p1=0, p2=0, sz1=Q[x].size(), sz2=P[y].size();
    while(p1<sz1 && p2<sz2){
        int x1=Q[x][p1].first, x2=P[y][p2];
        int t1=Q[x][p1].second?3:1, t2=2;
        if(x1<x2 || (x1==x2 && t1<t2)){
            if(t1==1) cnt++;
            else cnt--;
            p1++;
        }
        else ans+=cnt, p2++;
    }
    while(p1<sz1){
        if(Q[x][p1].second) cnt--;
        else cnt++;
        p1++;
    }
    while(p2<sz2){
        ans+=cnt; p2++;
    }
    return ans;
}

int main(){
    ios::sync_with_stdio(0); cin.tie(0);
    cin>>n>>r>>q;
    for(int i=1; i<=n; i++){
        int a,b;
        if(i==1){
            cin>>a; H[i]=a;
        }
        else{
            cin>>a>>b;
            G[a].push_back(i); H[i]=b;
        }
    }
    init();
    for(; q--; ){
        int r1, r2; cin>>r1>>r2;
        out(solve(r1,r2));
    }
    return 0;
}

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