Submission #403928

#	Time	Username	Problem	Language	Result	Execution time	Memory
403928		silverfish	Index (COCI21_index)	C++17	110 / 110	2238 ms	133532 KiB

index

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

typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int uint;
typedef pair<int, int> pii;
//mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

#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, p[N];

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;
		return;
	}

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

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

	for(int i = 0; i < n; ++i){
		cin >> p[i];
	}

	root[0] = new node;

	build(root[0], 1, N);

	for(int i = 1; i <= n; ++i){
		root[i] = new node;	
		add(p[i-1], root[i-1], root[i], 1, N); 
	}
	
	while(q--){
		int l, r; cin >> l >> r;
		int ans = 0;
		for(int j = 18; j >= 0; --j){
			int nans = ans + (1<<j);
			if(nans > N) continue;
			if(get(nans, N, root[r], 1, N) - get(nans, N, root[l-1], 1, N) >= nans) ans += (1<<j);
		}
		cout << ans << '\n';
	}

	return 0;
}

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