Submission #757989

#	Time	Username	Problem	Language	Result	Execution time	Memory
757989		SanguineChameleon	Archery (IOI09_archery)	C++17	68 / 100	2085 ms	4024 KiB

archery

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

void just_do_it();

int main() {
	#ifdef KAMIRULEZ
		freopen("kamirulez.inp", "r", stdin);
		freopen("kamirulez.out", "w", stdout);
	#endif
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	just_do_it();
	return 0;
}

const int maxN = 2e5 + 20;
int a[maxN * 2];
int cnt1[maxN];
int cnt2[maxN];
int N, R, K;

void simulate(int start, int lim, int cnt[]) {
	for (int i = 1; i <= N; i++) {
		cnt[i] = 0;
	}
	for (int i = 1; i <= start * 2 - 1; i++) {
		if (a[i] >= lim) {
			cnt[(i + 1) / 2]++;
		}
	}
	if (K >= lim) {
		cnt[start]++;
	}
	for (int i = start * 2; i <= N * 2 - 1; i++) {
		if (a[i] >= lim) {
			cnt[i / 2 + 1]++;
		}
	}
	vector<int> free;
	vector<int> holes;
	for (int i = 1; i <= N; i++) {
		if (cnt[i] == 2) {
			if (!holes.empty()) {
				cnt[holes.back()] = 1;
				holes.pop_back();
			}
			else {
				free.push_back(i);
			}
			cnt[i] = 1;
		}
		else {
			if (cnt[1] == 1) {
				free.push_back(i);
				cnt[1] = 0;
			}
			if (cnt[i] == 0 && i > 1) {
				holes.push_back(i);
			}
		}
	}
	reverse(free.begin(), free.end());
	for (int i = N; i > 1 && !free.empty(); i--) {
		if (cnt[i] == 0) {
			free.pop_back();
			cnt[i] = 1;
		}
	}
	for (auto i: free) {
		cnt[((i - 1) + N - R % N) % N + 1]++;
	}
}

int solve(int start) {
	if (start == 1) {
		simulate(start, K, cnt1);
	}
	else if (a[start * 2 - 2] < K) {
		if (a[start * 2 - 3] < K) {
			if (a[start * 2 - 1] < K) {
				if (cnt1[start] == 0) {
					cnt1[start - 1] = 0;
					cnt1[start] = 1;
				}
			}
		}
		else {
			if (a[start * 2 - 1] >= K) {
				if (cnt1[((start - 2) + N - R % N) % N + 1] == 2) {
					cnt1[((start - 2) + N - R % N) % N + 1] = 1;
					cnt1[((start - 1) + N - R % N) % N + 1] = 2;
				}
			}
			else {
				simulate(start, K, cnt1);
			}
		}
	}
	if (start == 1 || (a[start * 2 - 2] > K)) {
		simulate(start, K + 1, cnt2);
	}
	for (int i = 1; i <= N; i++) {
		if (cnt1[i] != cnt2[i]) {
			return i;
		}
	}
	return -1;
}

void just_do_it() {
	cin >> N >> R >> K;
	for (int i = 1; i <= N * 2 - 1; i++) {
		cin >> a[i];
	}
	if (N == 1) {
		cout << 1;
		return;
	}
	if (K == 1) {
		cout << N;
		return;
	}
	if (K == N * 2) {
		cout << 2;
		return;
	}
	pair<int, int> res = make_pair(N + 1, 0);
	for (int i = 1; i <= N; i++) {
		res = min(res, make_pair(solve(i), -i));
	}
	cout << -res.second;
}

• Subtask 1: 6 / 6
• Subtask 2: 62 / 94