Submission #928262

#	Time	Username	Problem	Language	Result	Execution time	Memory
928262		pcc	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	315 ms	1039188 KiB

Main

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

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,popcnt,sse4")

#define ll long long
#define pll pair<ll,ll>
#define fs first
#define sc second
#define ld double

const ll inf = 1e12;
const ll mxn = 510;
pll arr[mxn];
ll N,K;
ld dp[mxn][mxn][mxn];
multiset<ll> st;

int main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>N>>K;
	for(int i = 1;i<=N;i++)cin>>arr[i].sc>>arr[i].fs,arr[i].fs = (arr[i].fs == -1?inf:arr[i].fs);
	sort(arr+1,arr+N+1);
	for(auto &i:dp)for(auto &j:i)for(auto &k:j)k = inf;

	for(int i = 0;i<=N;i++)dp[0][i][0] = 0;
	for(int i = 1;i<=N;i++){
		//for(int j = 0;j<=N;j++){
		for(int j = 0;j<=N;j++){
			for(int k = 0;k<=j;k++){
				auto tmp = dp[i-1][j][k];
				dp[i][j][k] = min(dp[i][j][k],tmp+arr[i].sc/ld(j+1));
				dp[i][j][k+1] = min(dp[i][j][k+1],tmp+(arr[i].fs)/ld(k+1));
			}
		}
	}

	/*
	for(int i = 0;i<=N;i++){
		for(int j = 0;j<=i;j++)cout<<i<<' '<<j<<":"<<dp[i][j][j]<<endl;
	}cout<<endl;

   */

	ld ans = inf;
	for(int i = N;i>K;i--){
		st.insert(arr[i].sc);
	}
	for(int i = K;i>=0;i--){
		ll sum = 0,C = K-i;
		for(auto it = st.begin();C&&it != st.end();it++,C--){
			sum += *it;
		}
		for(int j = 0;j<=i;j++){
			ld tans = sum/ld(j+1)+dp[i][j][j];
			ans = min(ans,tans);
		}
		st.insert(arr[i].sc);
	}
	cout<<fixed<<setprecision(20)<<ans<<'\n';
	return 0;
}

• 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