Submission #1304002

#	Time	Username	Problem	Language	Result	Execution time	Memory
1304002		mantaggez	Watching (JOI13_watching)	C++20	100 / 100	146 ms	16152 KiB

watching

#include <bits/stdc++.h>

using namespace std;

const int nx = 2e3+5;

int n, p, q, l = 0, r = 1e9;
int dp[nx][nx], s[nx], b[nx];
vector<int> event(nx);

bool check(int w)
{
	for(int i=1;i<=n;i++)
	{
		s[i] = upper_bound(event.begin() + 1, event.begin() + n + 1, event[i] - w) - event.begin();
		b[i] = upper_bound(event.begin() + 1, event.begin() + n + 1, event[i] - 2 * w) - event.begin();
	}
	
	dp[0][0] = 0;
	for(int i=1;i<=n;i++)
	{
		dp[i][0] = dp[b[i] - 1][0] + 1;
		for (int j=1;j<=p;j++)
		{
			dp[i][j] = dp[i][j - 1];
			dp[i][j] = min({dp[i][j], dp[s[i] - 1][j - 1], dp[b[i] - 1][j] + 1});
		}
	}
	
	return dp[n][p] <= q;
}

int main()
{
	cin.tie(NULL)->sync_with_stdio(false);
	cin >> n >> p >> q;
	for(int i=1;i<=n;i++) cin >> event[i];
	
	sort(event.begin() + 1, event.begin() + n + 1);
	
	if(p >= n || q >= n)
	{
		cout << 1;
		return 0;
	}
	
	while(l < r)
	{
		int mid = (l + r) / 2;
		bool ok = check(mid);
		if(ok) r = mid;
		else l = mid + 1;
	}
	
	cout << l;
	
	return 0;
}

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