Submission #321096

#	Time	Username	Problem	Language	Result	Execution time	Memory
321096		super_j6	Regions (IOI09_regions)	C++14	100 / 100	7551 ms	45008 KiB

regions

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <string.h>
#include <vector>
using namespace std;
//#define endl '\n'
#define ll long long
#define pi pair<int, int>
#define f first
#define s second

const int mxn = 200001, mxk = 25000, m = 447;
int n, k, q, t;
int a[mxn], p[mxn], dp[mxn], l[mxn], r[mxn], bit[mxn], b[mxk];
ll f1[m][mxk], f2[m][mxk];
vector<int> g[mxn], w[mxk];

void add(int x, int v){
	for(x++; x <= n; x += x & -x) bit[x] += v;
}

int qry(int x){
	int ret = 0;
	for(x++; x; x -= x & -x) ret += bit[x];
	return ret;
}

int dfs(int c){
	r[c] = l[c];
	for(int i : g[c]) if(i != p[c]) l[i] = r[c] + 1, r[c] = dfs(i);
	return r[c];
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n >> k >> q;
	
	for(int i = 0; i < n; i++){
		if(i){
			cin >> p[i];
			g[--p[i]].push_back(i);
		}else{
			p[i] = -1;
		}
		cin >> a[i];
		w[--a[i]].push_back(i);
	}
	
	for(int i = 0; i < k; i++){
		if(w[i].size() > m){
			for(int j = 0; j < n; j++){
				f1[t][a[j]] += (dp[j] = (a[j] == i) + (~p[j] ? dp[p[j]] : 0));
			}
			memset(dp, 0, sizeof(dp));
			for(int j = n - 1; ~j; j--){
				f2[t][a[j]] += (dp[j] += a[j] == i);
				if(~p[j]) dp[p[j]] += dp[j];
	 		}
	 		b[i] = t++;
		}else{
			b[i] = -1;
		}
	}
	
	dfs(0);
	
	while(q--){
		int x, y;
		cin >> x >> y;
		x--, y--;
		if(~b[x]){
			cout << f1[b[x]][y] << endl;
		}else if(~b[y]){
			cout << f2[b[y]][x] << endl;
		}else{
			ll ret = 0;
			for(int i : w[y]) add(l[i], 1);
			for(int i : w[x]) ret += qry(r[i]) - qry(l[i] - 1);
			for(int i : w[y]) add(l[i], -1);
			cout << ret << endl;
		}
	}

	return 0;
}

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