Submission #494638

#	Time	Username	Problem	Language	Result	Execution time	Memory
494638		aryan12	medians (balkan11_medians)	C++17	100 / 100	139 ms	17416 KiB

medians

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

mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());

const int N = 2e5 + 5;
int seg[N * 4];

void Upd(int l, int r, int pos, int qpos) {
	if(l == r) {
		seg[pos]++;
		return;
	}
	int mid = (l + r) >> 1;
	if(qpos <= mid) Upd(l, mid, pos * 2, qpos);
	else Upd(mid + 1, r, pos * 2 + 1, qpos);
	seg[pos] = seg[pos * 2] + seg[pos * 2 + 1];
}

int Query(int l, int r, int pos, int ql, int qr) {
	if(ql <= l && r <= qr) {
		return seg[pos];
	}
	if(ql > r || l > qr) {
		return 0;
	}
	int mid = (l + r) >> 1;
	return Query(l, mid, pos * 2, ql, qr) + Query(mid + 1, r, pos * 2 + 1, ql, qr);
}

void Solve() {
	int n;
	cin >> n;
	int b[n + 1];
	for(int i = 1; i <= n; i++) {
		cin >> b[i];
	}
	int a[n * 2 + 1];
	set<int> s;
	for(int i = 1; i < 2 * n; i++) {
		s.insert(i);
	}
	for(int i = 1; i < n * 2; i++) {
		a[i] = 0;
	}
	vector<int> ans;
	ans.push_back(b[1]);
	a[b[1]] = 1;
	s.erase(b[1]);
	/*for(auto i: s) {
		cout << i << " ";
	}
	cout << endl;*/
	//cout << "first val = " << b[1] << endl;
	Upd(1, 2 * n - 1, 1, b[1]);
	for(int i = 2; i <= n; i++) {
		//cout << "i = " << i << endl;
		if(a[b[i]] == 1) {
			int ans1 = Query(1, 2 * n - 1, 1, 1, b[i] - 1), ans2 = Query(1, 2 * n - 1, 1, b[i] + 1, 2 * n - 1);
			assert(ans1 - ans2 == -2 || ans1 - ans2 == 0 || ans1 - ans2 == 2);
			//cout << "ans1 = " << ans1 << ", ans2 = " << ans2 << "\n";
			int st = ((ans1 - ans2) == -2) ? 2 : ((ans1 - ans2 == 0) ? 1 : 0);
			int en = ((ans1 - ans2) == 2) ? 2 : ((ans1 - ans2 == 0) ? 1 : 0);
			while(st != 0) {
				//cout << "hey" << endl;
				assert(s.size() != 0);
				/*for(auto j: s) {
					cout << j << " ";
				}
				cout << endl;*/
				//cout << "ok" << endl;
				/*for(auto j: s) {
					cout << j << " ";
				}*/
				//cout << endl;
				auto f = s.begin();
				//cout << "bro " << *f << endl;
				int x = *f;
				s.erase(*f);
				//cout << "omg " << *(f) << endl;
				ans.push_back(x);
				//cout << ans[ans.size() - 1] << "\n";
				//cout << (*f) << endl;
				//cout << "ok" << endl;
				a[x] = 1;
				//cout << "omk" << endl;
				Upd(1, 2 * n - 1, 1, x);
				//cout << "val = " << *f << endl;
				st--;
				/*for(auto j: s) {
					cout << j << " ";
				}
				cout << endl;*/
			}
			while(en != 0) {
				//cout << "hey" << endl;
				assert(s.size() != 0);
				auto f = --s.end();
				int x = *f;
				s.erase(*f);
				ans.push_back(x);
				a[x] = 1;
				Upd(1, 2 * n - 1, 1, x);
				//cout << "value = " << *f << endl;
				en--;
			}
		}
		else {
			ans.push_back(b[i]);
			a[b[i]] = 1;
			//cout << "Upd value = " << b[i] << endl;
			s.erase(b[i]);
			Upd(1, 2 * n - 1, 1, b[i]);
			int ans1 = Query(1, 2 * n - 1, 1, 1, b[i] - 1), ans2 = Query(1, 2 * n - 1, 1, b[i] + 1, 2 * n - 1);
			assert(abs(ans1 - ans2) == 1);
			if(ans1 < ans2) {
				assert(s.size() != 0);
				auto f = s.begin();
				int x = *f;
				s.erase(*f);
				ans.push_back(x);
				a[x] = 1;
				//cout << "Val = " << *f << endl;
				Upd(1, 2 * n - 1, 1, x);
			}
			else {
				assert(s.size() != 0);
				auto f = --s.end();
				int x = *f;
				s.erase(*f);
				ans.push_back(x);
				a[x] = 1;
				//cout << "Value = " << *f << endl;
				Upd(1, 2 * n - 1, 1, x);
			}
		}
		/*for(auto j: s) {
			cout << j << " ";
		}
		cout << endl;*/
	}
	assert(s.size() == 0);
	for(int i = 0; i < ans.size(); i++) {
		cout << ans[i] << " ";
	}
	cout << "\n";
}

int32_t main() {
	auto begin = std::chrono::high_resolution_clock::now();
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int t = 1;
	//cin >> t;
	while(t--) {
		Solve();
	}
	auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n"; 
	return 0;
}

Compilation message (stderr)

medians.cpp: In function 'void Solve()':
medians.cpp:144:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  144 |  for(int i = 0; i < ans.size(); i++) {
      |                 ~~^~~~~~~~~~~~

• Subtask 1: 65 / 65
• Subtask 2: 35 / 35