Submission #1043425

#	Time	Username	Problem	Language	Result	Execution time	Memory
1043425		Lucpp	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	362 ms	2816 KiB

Main

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define sz(x) (int)size(x)
#define all(x) (x).begin(), (x).end()
constexpr double inf = 1e18;

double pmin(double &a, double b){
	return a = min(a, b);
}

int main(){
	cin.tie(0)->sync_with_stdio(false);
	int n, k;
	cin >> n >> k;
	vector<double> a(n), b(n);
	for(int i = 0; i < n; i++){
		cin >> a[i] >> b[i];
		if(b[i] < 0) b[i] = inf;
	}
	{
		vector<int> ord(n);
		for(int i = 0; i < n; i++) ord[i] = i;
		sort(all(ord), [&](int i, int j){return b[i] < b[j];});
		vector<double> a2(n), b2(n);
		for(int i = 0; i < n; i++) a2[i] = a[ord[i]], b2[i] = b[ord[i]];
		a = a2, b = b2;
	}
	vector<int> ordA(n);
	for(int i = 0; i < n; i++) ordA[i] = i;
	sort(all(ordA), [&](int i, int j){return a[i] < a[j];});
	double ans = inf;
	for(int l = 0; l <= k; l++){
		vector<vector<double>> dp(k+1, vector<double>(l+1, inf));
		dp[0][0] = 0;
		for(int i = 0; i < k; i++){
			for(int j = 0; j <= l; j++){
				if(j < l) pmin(dp[i+1][j+1], dp[i][j] + b[i] / (1+j));
				pmin(dp[i+1][j], dp[i][j] + a[i] / (1+l));
			}
		}
		for(int i = l; i <= k; i++){
			double val = dp[i][l];
			int cnt = i;
			for(int j : ordA){
				if(j >= i && cnt < k){
					val += a[j] / (1+l);
					cnt++;
				}
			}
			ans = min(ans, val);
		}
	}
	cout << setprecision(6) << fixed << ans << "\n";
}

• 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