Submission #256830

#	Time	Username	Problem	Language	Result	Execution time	Memory
256830		islingr	Watching (JOI13_watching)	C++17	100 / 100	178 ms	16536 KiB

watching

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

const int N = 1 << 11;
int n, P, Q, a[N], dp[N][N];

bool f(int w) {
	for (int i = 1; i <= n; ++i) {
		int j = i, k = i;
		while (j && a[i] - a[j] < w) --j;
		while (k && a[i] - a[k] < 2 * w) --k;
		dp[i][0] = 1 + dp[k][0];
		for (int p = 1; p <= P; ++p) dp[i][p] = min(dp[j][p - 1], 1 + dp[k][p]);
	}
	return dp[n][P] <= Q;
}

signed main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	cin >> n >> P >> Q;
	for (int i = 1; i <= n; ++i) cin >> a[i];
	if (n <= P) return cout << 1, 0;
	sort(a + 1, a + n + 1);
	int l = 0, r = a[n] - a[1] + 1;
	while (r - l > 1) {
		int m = l + (r - l + 1) / 2;
		(f(m) ? r : l) = m;
	}
	cout << r;
}

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