oj.uz

Submission #156436

# Submission time Handle Problem Language Result Execution time Memory
156436 2019-10-05T16:00:13 Z Saboon Watching (JOI13_watching) C++14
100 / 100
 187 ms 508 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int mod = 1e9 + 7;
const int maxn = 2e3 + 10;

int n, p, q, a[maxn];
int dp[2][maxn];
int nexlow[maxn], nexhig[maxn];

bool check(int w){
	for (int i = 0; i < n; i++){
		nexlow[i] = lower_bound(a, a + n, a[i] + w) - a - 1;
		nexhig[i] = lower_bound(a, a + n, a[i] + 2 * w) - a - 1;
	}
	nexlow[n] = nexhig[n] = n - 1;
	for (int i = 0; i <= p; i++){
		int x = i % 2;
		for (int j = 0; j <= q; j++){
			dp[x][j] = -1;
			if (i > 0)
				dp[x][j] = max(dp[x][j], nexlow[dp[1 - x][j] + 1]);
			if (j > 0)
				dp[x][j] = max(dp[x][j], nexhig[dp[x][j - 1] + 1]);
		}
	}
	return (dp[p%2][q] == n - 1);
}

int main(){
	ios_base::sync_with_stdio (false);
	cin >> n >> p >> q;
	for (int i = 0; i < n; i++)
		cin >> a[i];
	sort(a, a + n);
	if (p + q >= n)
		return cout << 1 << endl, 0;
	int lo = 1, hi = 1000000000 + 1;
	while (hi - lo > 1){
		int mid = (lo + hi) >> 1;
		if (check(mid) == true)
			hi = mid;
		else
			lo = mid;
	}
	cout << hi << endl;
}

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 508 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 3 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 376 KB Output is correct
9 Correct 2 ms 376 KB Output is correct
10 Correct 3 ms 376 KB Output is correct
11 Correct 8 ms 376 KB Output is correct
12 Correct 3 ms 376 KB Output is correct
13 Correct 2 ms 376 KB Output is correct
14 Correct 1 ms 376 KB Output is correct
15 Correct 2 ms 376 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 6 ms 376 KB Output is correct
8 Correct 25 ms 380 KB Output is correct
9 Correct 25 ms 504 KB Output is correct
10 Correct 37 ms 432 KB Output is correct
11 Correct 40 ms 376 KB Output is correct
12 Correct 187 ms 504 KB Output is correct
13 Correct 9 ms 376 KB Output is correct
14 Correct 9 ms 376 KB Output is correct
15 Correct 9 ms 376 KB Output is correct