Submission #1177794

#	Time	Username	Problem	Language	Result	Execution time	Memory
1177794		Nonoze	Index (COCI21_index)	C++17	110 / 110	730 ms	33104 KiB

index

/*
*	Author: Nonoze
*	Created: Wednesday 02/04/2025
*/
#include <bits/stdc++.h>
using namespace std;

#ifndef DEBUG
	#define dbg(...)
#endif

// #define cout cerr << "OUT: "
#define endl '\n'
#define endlfl '\n' << flush
#define quit(x) return (void)(cout << x << endl)

template<typename T> void read(T& x) { cin >> x;}
template<typename T1, typename T2> void read(pair<T1, T2>& p) { read(p.first), read(p.second);}
template<typename T> void read(vector<T>& v) { for (auto& x : v) read(x); }
template<typename T1, typename T2> void read(T1& x, T2& y) { read(x), read(y); }
template<typename T1, typename T2, typename T3> void read(T1& x, T2& y, T3& z) { read(x), read(y), read(z); }
template<typename T1, typename T2, typename T3, typename T4> void read(T1& x, T2& y, T3& z, T4& zz) { read(x), read(y), read(z), read(zz); }
template<typename T> void print(vector<T>& v) { for (auto& x : v) cout << x << ' '; cout << endl; }

#define sz(x) (int)(x.size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define make_unique(v) sort(all(v)), v.erase(unique(all(v)), (v).end())
#define pb push_back
#define mp(a, b) make_pair(a, b)
#define fi first
#define se second
#define cmin(a, b) a = min(a, b)
#define cmax(a, b) a = max(a, b)
#define YES cout << "YES" << endl
#define NO cout << "NO" << endl
#define QYES quit("YES")
#define QNO quit("NO")

#define int long long
#define double long double
const int inf = numeric_limits<int>::max() / 4;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int MOD = 1e9+7, LOG=20;



void solve();

signed main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	int tt=1;
	// cin >> tt;
	while(tt--) solve();
	return 0;
}


template<class T>
struct segtree {
	vector<T> st;
	int n;
	T idElement;

	segtree() {}

	segtree(int nn, T idEl, vector<T> creation={}) {
		n=nn, idElement=idEl;
		st.resize(n*2, idElement);
		if (!creation.empty()) {
			for (int i=0; i<n; i++) st[i+n]=creation[i];
			build();
		}
	}

	void build() {
		for (int i=n-1; i>0; i--) st[i] = combine(st[i<<1], st[i<<1|1]);
	}
	
	void update(int p, T val) {
		for (st[p += n] = val; p > 1; p >>= 1) st[p>>1] = combine(st[p], st[p^1]);
	}

	T query(int l, int r) {
		T res = idElement;
		r++;
		for (l += n, r += n; l < r; l >>= 1, r >>= 1) {
			if (l&1) res = combine(res, st[l++]);
			if (r&1) res = combine(res, st[--r]);
		}
		return res;
	}

	T combine(T l, T r) {
		T ans=l+r;
		return ans;
	}
};


int n, k, m, q;
vector<int> a;


void solve() {
	read(n, q);
	a.clear(), a.resize(n); read(a);
	int mx=2e5 + 1;
	vector<vector<int>> appears(mx);
	for (int i=0; i<n; i++) appears[a[i]].pb(i);
	vector<int> ans(q, 0), L(q, 1), R(q, mx);
	vector<pair<int, int>> queries(q); read(queries);
	for (auto &u: queries) u.fi--, u.se--;
	while (1) {
		bool ok=0;
		vector<vector<int>> vec(mx);
		for (int i=0; i<q; i++) {
			if (L[i]<=R[i]) {
				vec[(L[i]+R[i])/2].pb(i);
				ok=1;
			}
		}
		if (!ok) break;

		
		segtree<int> st(n, 0);
		for (int val=mx-1; val>=0; val--) {
			for (auto &u: appears[val]) st.update(u, 1);
			for (auto &u: vec[val]) {
				int nb=st.query(queries[u].fi, queries[u].se);
				if (nb>=val) L[u]=val+1, ans[u]=val;
				else R[u]=val-1;
			}
		}
	}
	for (auto &u: ans) cout << u << endl;
}

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