Submission #1288422

#	Time	Username	Problem	Language	Result	Execution time	Memory
1288422		tunademayo	Let's Win the Election (JOI22_ho_t3)	C++20	16 / 100	6 ms	2432 KiB

Main

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

#define ll long long 
#define ld double

const bool Multitest = 0;

const int N = 505; const ll offset = 1e9;

int n, k;

struct Type 
{
	ld x, y;
}; Type a[N], b[N];

bool cmp1(Type a, Type b)
{
	return a.y < b.y || (a.y == b.y && a.x < b.x);
}
ld dp[N][N], f[N];

void minimize(ld& a, ld b)
{
	if(a > b) a = b;
}

ld cal(int p)
{
	if(f[p] > 0) return f[p];
	
	for (int i = 0; i <= n; ++i) {
        for (int j = 0; j <= k - p; ++j) {
            dp[i][j] = 1e9;
        }
    }
    dp[0][0] = 0;
    for (int i = 1; i <= n; ++i) {
        for (int j = 0; j <= min(i, k - p); ++j) {
            int x = i - j - 1;
            if (j > 0) {
                dp[i][j] = min(dp[i][j], dp[i - 1][j - 1] + 1.0 * a[i].x / (p + 1));
            }
            dp[i][j] = min(dp[i][j], dp[i - 1][j] + (x < p ? 1.0 * a[i].y / (x + 1) : 0));
        }
    }
	
	return f[p] = dp[n][k - p];
}

void work()
{
	cin >> n >> k;
	
	for(int i = 1 ; i <= n ; i++)
	{
		cin >> a[i].x >> a[i].y;
		if(a[i].y == -1) a[i].y = 1e9;
		f[i] = -1;
	}
	
	sort(a + 1, a + 1 + n, cmp1);
	ld ans = 1e18;
	
//	cerr << "dm";
//	
//	cout << cal(2);
////	
//	return;
	
	int l = 0, r = n - 1, pos = n;
	
	while(l <= r)
	{
		int mid = (l + r) >> 1;
		
		if(cal(mid) <= cal(mid + 1)) r = mid - 1, pos = mid;
		else l = mid + 1;
	}
	
	cout << setprecision(9) << fixed << f[pos];
}

int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);	cout.tie(0);

	int q = 1;
	
	if(Multitest)	cin >> q;
	
	while(q--) work();
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 5
• Subtask 3: 0 / 11
• Subtask 4: 0 / 12
• Subtask 5: 0 / 33
• Subtask 6: 11 / 11
• Subtask 7: 0 / 23