Submission #1278149

#	Time	Username	Problem	Language	Result	Execution time	Memory
1278149		nanaseyuzuki	Let's Win the Election (JOI22_ho_t3)	C++20	10 / 100	270 ms	4416 KiB

Main

#include <bits/stdc++.h>
// Author: Kazuki_Will_Win_VOI_8703
#define fi first
#define se second
#define pii pair<int, int>
#define ll long long
using namespace std;

const int mn = 5e2 + 5, lg2 = 20, mbit = (1 << 20) + 1, mm = 5e3 + 5;
const double INF = 1e100;

int n, K;

struct Megumi{
	int a, b;
	bool operator<(const Megumi& other) const{
		int bb = (b == -1 ? INT_MAX : b);
		int ob = (other.b == -1 ? INT_MAX : other.b);
		if(bb == ob) return a < other.a;
		return bb < ob;
	}
} e[mn];

double dp[2][mn][mn];

void solve(){
	cin >> n >> K;
	for(int i = 1; i <= n; i++){
		cin >> e[i].a >> e[i].b;
	}
	sort(e + 1, e + n + 1);
	for(int t = 0; t < 2; t++){
		for(int j = 0; j <= K; j++){
			for(int k = 0; k <= K; k++){
				dp[t][j][k] = INF;
			}
		}
	}
	dp[0][1][0] = 0.0;

	double ans = INF;
	for(int i = 1; i <= n; i++){
		int cur = i & 1;
		int pre = cur ^ 1;
		for(int j = 0; j <= K; j++){
			for(int k = 0; k <= K; k++){
				dp[cur][j][k] = INF;
			}
		}
		for(int j = 1; j <= K; j++){
			for(int k = 0; k <= K; k++){
				dp[cur][j][k] = min(dp[cur][j][k], dp[pre][j][k]);
				if(k >= 1 && dp[pre][j][k - 1] < INF){
					double cand = dp[pre][j][k - 1] + (double)e[i].a / (double)j;
					if(cand < dp[cur][j][k]) dp[cur][j][k] = cand;
				}
				if(e[i].b != -1 && j >= 2 && k >= 1 && dp[pre][j - 1][k - 1] < INF){
					double cand = dp[pre][j - 1][k - 1] + (double)e[i].b / (double)(j - 1);
					if(cand < dp[cur][j][k]) dp[cur][j][k] = cand;
				}
				if(k == K && dp[cur][j][k] < ans) ans = dp[cur][j][k];
			}
		}
	}

	cout << setprecision(15) << fixed << ans << '\n';
}

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int t = 1;
    // cin >> t;
    while(t--){
        solve();
    }
}

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