Submission #791746

#	Time	Username	Problem	Language	Result	Execution time	Memory
791746		acatmeowmeow	Watching (JOI13_watching)	C++11	100 / 100	202 ms	11868 KiB

watching

#include <bits/stdc++.h>

using namespace std;

#define int long long 

const int N = 2e3;
int n, p, q, arr[N + 5], nex[N + 5][2], dp[N + 5][N + 5];

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin >> n >> p >> q;
	for (int i = 1; i <= n; i++) cin >> arr[i];
	if (p + q >= n) { cout << 1 << '\n'; return 0; }
	sort(arr + 1, arr + n + 1);
	int l = 1, r = 1e9, ans = 1e9;
	while (l <= r) {
		int m = (l + r)/2;
		for (int i = 1; i <= n; i++) {
			for (int j = i; j <= n; j++) {
				if (arr[j] - arr[i] + 1 <= m) nex[i][0] = j;
				if (arr[j] - arr[i] + 1 <= 2*m) nex[i][1] = j;
			}
		}
		for (int i = 0; i <= p; i++) {
			for (int j = 0; j <= q; j++) {
				dp[i][j] = 0;
			}
		}
		for (int i = 0; i <= p; i++) {
			for (int j = 0; j <= q; j++) {
				dp[i + 1][j] = max(dp[i + 1][j], nex[min(n, dp[i][j] + 1)][0]);
				dp[i][j + 1] = max(dp[i][j + 1], nex[min(n, dp[i][j] + 1)][1]);
			}
		}
		if (dp[p][q] == n) ans = m, r = m - 1;
		else l = m +1;
	}
	cout << ans << '\n';
	return 0;
}

• Subtask 1: 50 / 50
• Subtask 2: 50 / 50