Submission #321029

#	Time	Username	Problem	Language	Result	Execution time	Memory
321029		w4123	Watching (JOI13_watching)	C++17	50 / 100	729 ms	262148 KiB

watching

#include <algorithm>
#include <iostream>
using namespace std;
int arr[2005];
int n, p, q;
 
int dp[2005][100005];
bool check(int mid)
{
	for (int i = 1; i <= n; i++)
	{
		for (int j = 0; j <= p; j++)
		{
			dp[i][j] = 1000000000;
		}
	}
	
	for (int i = 1; i <= n; i++)
	{
		int j1 = i - 1;
		while (j1 >= 1 && arr[i] - arr[j1] + 1 <= mid) j1--;
		int j2 = j1;
		while (j2 >= 1 && arr[i] - arr[j2] + 1 <= 2 * mid)j2--;
		// cout << j1 << " " << j2 << endl;
		for (int c = 0; c <= p; c++)
		{
			if (c > 0)dp[i][c] = min(dp[i][c], dp[j1][c - 1]);
			dp[i][c] = min(dp[i][c], dp[j2][c] + 1);
		}
	}
	return dp[n][p] <= q; 
}
 
int main()
{
 
	cin >> n >> p >> q;
	for (int i = 1; i <= n; i++)
	{
		cin >> arr[i];
	}
	sort(arr + 1, arr + n + 1);
 
	int l = 1, r = 1000000000;
	while(l < r)
	{
		int mid = l + (r - l) / 2;
		if (check(mid))
		{
			r = mid;
		}
		else
		{
			l = mid + 1;
		}
		//cout << l << " " << r << endl;
	}
	cout << r;
}

• Subtask 1: 50 / 50
• Subtask 2: 0 / 50