oj.uz

Submission #384198

# Submission time Handle Problem Language Result Execution time Memory
384198 2021-03-31T19:04:30 Z aryan12 Watching (JOI13_watching) C++17
50 / 100
 35 ms 8684 KB 
#include <bits/stdc++.h>
using namespace std;
#define int long long

const int N = 1010;
int a[N + 20];
int dp[N + 20][N + 20];
int n;

bool Cost(int w, int p, int q) {
	int forP[n + 1], forQ[n + 1];
	for(int i = 0; i <= n; i++) {
		forP[i] = 0;
		forQ[i] = 0;
	}
	int prev = 1;
	for(int i = 1; i <= n; i++) {
		for(int j = prev; j <= n; j++) {
			if(a[j] - a[i] >= w) {
				prev = j;
				break;
			}
			else if(j == n) {
				prev = n + 1;
			}
		}
		forP[i] = prev - 1;
	}
	prev = 1;
	for(int i = 1; i <= n; i++) {
		for(int j = prev; j <= n; j++) {
			if(a[j] - a[i] >= 2 * w) {
				prev = j;
				break;
			}
			else if(j == n) {
				prev = n + 1;
			}
		}
		forQ[i] = prev - 1;
	}
	/*cout << "forP array\n";
	for(int i = 1; i <= n; i++) {
		cout << forP[i] << " ";
	}
	cout << "\n";
	cout << "forQ array\n";
	for(int i = 1; i <= n; i++) {
		cout << forQ[i] << " ";
	}
	cout << "\n";*/
	for(int i = 0; i < N; i++) {
		for(int j = 0; j < N; j++) {
			dp[i][j] = 0;
		}
	}
	for(int i = 1; i <= p; i++) {
		dp[i][0] = (dp[i - 1][0] == n) ? dp[i - 1][0] : forP[dp[i - 1][0] + 1];
	}
	for(int j = 1; j <= q; j++) {
		dp[0][j] = (dp[0][j - 1] == n) ? dp[0][j - 1] : forQ[dp[0][j - 1] + 1];
	}
	for(int i = 1; i <= p; i++) {
		for(int j = 1; j <= q; j++) {
			if(dp[i - 1][j] == n || dp[i][j - 1] == n) {
				dp[i][j] = n;
				continue;
			}
			dp[i][j] = max((forP[dp[i - 1][j] + 1]), (forQ[dp[i][j - 1] + 1]));
		}
	}
	if(dp[p][q] == n)
		return true;
	return false;
}

void Solve() {
	int p, q;
	cin >> n >> p >> q;
	for(int i = 1; i <= n; i++) {
		cin >> a[i];
	}
	sort(a + 1, a + 1 + n);
	if(p + q >= n) {
		cout << "1\n";
		return;
	}
	int left = 1, right = 1e9;
	int mid, ans = 1e9 + 1;
	while(left <= right) {
		//cout << "left = " << left << ", right = " << right << "\n";
		mid = (left + right) / 2;
		//cout << "mid = " << mid << "\n";
		if(Cost(mid, p, q)) {
			//cout << "mid is coming true\n";
			right = mid - 1;
			ans = mid;
		}
		else {
			//cout << "mid is coming false\n";
			left = mid + 1;
		}
	}
	cout << ans << "\n";
}

int32_t main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	Solve();
	return 0;
}

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 29 ms 8428 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 32 ms 8428 KB Output is correct
4 Correct 2 ms 364 KB Output is correct
5 Correct 1 ms 384 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 33 ms 8428 KB Output is correct
8 Correct 29 ms 8448 KB Output is correct
9 Correct 28 ms 8448 KB Output is correct
10 Correct 32 ms 8684 KB Output is correct
11 Correct 29 ms 8428 KB Output is correct
12 Correct 30 ms 8428 KB Output is correct
13 Correct 31 ms 8428 KB Output is correct
14 Correct 29 ms 8428 KB Output is correct
15 Correct 35 ms 8428 KB Output is correct

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Runtime error 2 ms 620 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -