Submission #896390

#	Time	Username	Problem	Language	Result	Execution time	Memory
896390		arashMLG	Regions (IOI09_regions)	C++17	100 / 100	5704 ms	75568 KiB

regions

#include<bits/stdc++.h>
#ifdef LOCAL
#include "Essentials/algo/debug.h"
#else
#define debug(...) 69
#endif
using namespace std;

typedef long long     ll;
typedef pair<int,int> pii;
typedef pair<ll,ll>   pll;

const int sq = 600;
const int N = 2e5 + 23;
const ll inf = 1e18;

#define F           first
#define S           second
#define pb          push_back
#define kill(x)     cout<<x<<endl, exit(0);
#define all(x)      x.begin(),x.end()
#define sz(x)       (int)x.size()
#define lc          (v << 1)
#define rc          ((v<<1) |1)

struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};


struct Fen {
	int bit[N];
	
	void add(int pos,int x) {
		for(; pos < N; pos += pos&-pos)
			bit[pos] += x;
	}
	
	void add(int l,int r,int x) {
		add(l,x);
		add(r+1,-x);
	}
	
	int get(int pos) {
		int ans=0;
		for(; pos > 0 ; pos -= pos&-pos)
			ans += bit[pos];
		return ans;
	}
} fen;

int n,r,q;
vector<int> G[N];
int psu[N],psd[N];
int h[N];
vector<int> com[N];
unordered_map<int,int,custom_hash> mp[N];
int st[N],ft[N];
int timer = 1;

void dfsset(int v) {
	st[v] = timer ++;
	for(int u : G[v]) dfsset(u);
	ft[v] = timer-1;
}

void dfs(int v,int cur_r) {
	psu[v] += (h[v] == cur_r);
	psd[v] = (h[v] == cur_r);
	
	for(int u : G[v]) {
		psu[u] = psu[v];
		dfs(u,cur_r);
		psd[v] += psd[u];
	}
	if(sz(com[h[v]]) < sq || h[v] > cur_r) {
		mp[cur_r][h[v]] += psu[v];
		mp[h[v]][cur_r] += psd[v];
	}
	if(v == 1) psu[v] = psd[v] = 0;
}

int32_t main() {
    cin.tie(nullptr)->sync_with_stdio(false);
	cin>>n>>r>>q;
	for(int i = 1; i <= n ; i++) {
		if(i >= 2) {
			int p; cin>>p;
			G[p].pb(i);
		}
		cin>>h[i];
		com[h[i]].pb(i);
		
	}
	dfsset(1);
	for(int i = 1; i<= r; i ++) {
		if(sz(com[i]) >= sq) {
			dfs(1,i);
		}
	}
	while(q--) {
		int r1,r2; cin>>r1>>r2;
		if(sz(com[r1]) >= sq || sz(com[r2]) >= sq){
			cout<<mp[r1][r2] << endl;
			continue;
		}
		int ans=0;
		for(int x : com[r1]) {
			fen.add(st[x],ft[x],1);
		}
		for(int x : com[r2]) {
			ans += fen.get(st[x]);
		}
		for(int x : com[r1]) {
			fen.add(st[x],ft[x],-1);
		}
		cout<<ans << endl;
	}
	return 0;
}

// Jumpsuit, Jumpsuit cover me!
// Jumpsuit, Jumpsuit cover me!

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