Submission #403842

#	Time	Username	Problem	Language	Result	Execution time	Memory
403842		silverfish	Index (COCI21_index)	C++14	60 / 110	2565 ms	137416 KiB

index

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int uint;

#define pb push_back
#define FAST ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define TC int __TC__; cin >> __TC__; while(__TC__--)
#define ar array

const int INF = 1e9 + 7, N = 2e5;

int n, q;

struct node{
	node* left = nullptr,* right = nullptr;
	int v = 0;
};

node* root[N+1];

void build(node *rt, int lx, int rx){
	if(lx == rx) return;
	int m = lx+(rx-lx) / 2;

	rt->left = new node;
	rt->right = new node;
	build(rt->left, lx, m);
	build(rt->right, m+1, rx);
	return;
}

void add(int pos, node* lr, node* nr, int lx, int rx){
	if(lx == rx){
		nr->v=1;
		return;
	}

	int m = lx + (rx - lx) / 2;

	if(pos <= m){ // go left
		nr->right = lr->right;
		nr->left = new node;
		add(pos, lr->left, nr->left, lx, m);
	}else{ // go right
		nr->left = lr->left;
		nr->right = new node;
		add(pos, lr->right, nr->right, m+1, rx);
	}
	nr->v = nr->left->v + nr->right->v;
}

int get(int l, int r, node* rt, int lx, int rx){
	if(r < lx || l > rx) return 0;
	if(lx >= l && rx <= r) return rt->v;
	int m = lx + (rx - lx) / 2;

	return get(l, r, rt->left, lx, m) + get(l, r, rt->right, m+1, rx);
}

int main(void)
{
	FAST;
	cin >> n >> q;
	vector<ar<int,2>> a(n);
	for(int i = 0; i < n; ++i){
		cin >> a[i][0];
		a[i][1] = i+1;
	}

	sort(a.rbegin(), a.rend());


	root[0] = new node;
	build(root[0], 1, n);
	for(int i = 1; i <= n; ++i){
		root[i] = new node;	
		add(a[i-1][1], root[i-1], root[i], 1, n); 
	}
	
	sort(a.begin(), a.end());
	while(q--){
		int l, r; cin >> l >> r;
		int ans = 1;
		for(int j = 22; j >= 0; --j){
			int nans = ans + (1<<j);
			auto it = lower_bound(a.begin(), a.end(), ar<int,2>{nans, 0});
			if(it == a.end()) continue;
			int pos = n-(it - a.begin());
			if(get(l, r, root[pos], 1, n) >= nans) ans += (1<<j);
		}
		cout << ans << '\n';
	}

	return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 0 / 50