Submission #1248851

#	Time	Username	Problem	Language	Result	Execution time	Memory
1248851		arashmemar	Let's Win the Election (JOI22_ho_t3)	C++20	100 / 100	583 ms	492592 KiB

Main

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

const int maxn = 501;

pair <int, int> a[maxn];

float dp[maxn][maxn][maxn];
int n, k;
float get(int c)
{
	for (int i = 1;i <= n;i++)
	{
		for (int x = max(0, c - n + i);x <= min(i, c);x++)
		{
			for (int xp = max(0, k - x - n + i);xp <= min(i - x, k - x);xp++)
			{
				dp[i][x][xp] = dp[i - 1][x][xp];
				if (x + xp > i - 1)
				{
					dp[i][x][xp] = 1e18;
				}
				if (x)
				{
					dp[i][x][xp] = min(dp[i][x][xp], dp[i - 1][x - 1][xp] + (float)a[i].first / x);
				}
				if (xp)
				{
					dp[i][x][xp] = min(dp[i][x][xp], dp[i - 1][x][xp - 1] + (float)a[i].second / (c + 1));
				}
			}
		}
	}
	return dp[n][c][k - c];
}

int main()
{
	cout << setprecision(20);
	cin >> n >> k;
	for (int i = 1;i <= n;i++)
	{
		cin >> a[i].second >> a[i].first;
		if (a[i].first == -1)
		{
			a[i].first = maxn * maxn * maxn;
		}
	}
	sort(a + 1 , a + n + 1);

	for (int x = 0;x <= n;x++)
	{
		for (int i = 0;i <= n;i++)
		{
			for (int j = 0;j <= n;j++)
			{
				dp[x][i][j] = 1e18;
			}
		}
	}
	dp[0][0][0] = 0;

	float ans = get(0);

	int l = 0, r = k + 1;
	while (r - l > 1)
	{
		int mid = (l + r) / 2;
		float cur = get(mid), pre = get(mid - 1);
		ans = min(ans, min(cur, pre));
		if (cur > pre)
		{
			r = mid;
		}
		else
		{
			l = mid;
		}
	}

	cout << ans;
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 11 / 11
• Subtask 4: 12 / 12
• Subtask 5: 33 / 33
• Subtask 6: 11 / 11
• Subtask 7: 23 / 23