Submission #921305

#	Time	Username	Problem	Language	Result	Execution time	Memory
921305		KiaRez	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	1169 ms	12888 KiB

Main

/*
    IN THE NAME OF GOD
*/
#include <bits/stdc++.h>

// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
typedef long double ld;

#define F                                      first
#define S                                      second
#define Mp                                     make_pair
#define pb                                     push_back
#define pf                                     push_front
#define size(x)                                ((ll)x.size())
#define all(x)                                 (x).begin(),(x).end()
#define kill(x)		                           cout << x << '\n', exit(0);
#define fuck(x)                                cout << "(" << #x << " , " << x << ")" << endl
#define endl                                   '\n'

const int N = 3e5+23, lg = 18;
ll Mod = 1e9+7; //998244353;

inline ll MOD(ll a, ll mod=Mod) {a%=mod; (a<0)&&(a+=mod); return a;}
inline ll poww(ll a, ll b, ll mod=Mod) {
    ll ans = 1;
    a=MOD(a, mod);
    while (b) {
        if (b & 1) ans = MOD(ans*a, mod);
        b >>= 1;
        a = MOD(a*a, mod);
    }
    return ans;
}

int n, k, A[N], B[N];
ld dp[505][505], pd[505][505];
pair<ld, ld> x[N], y[N];

ld check(int mid) {
	for(int i=0; i<=n; i++) fill(dp[i], dp[i]+k+2, 1e9);
	ld ans = 1e9;
	dp[0][0] = 0;
	for(int i=1; i<=n; i++) {
	for(int j=0; j<=i&&j<=k; j++) {
		if(j>0) dp[i][j] = min(dp[i][j], dp[i-1][j-1]+x[i].F/(ld)(j));
		dp[i][j] = min(dp[i][j], dp[i-1][j]+x[i].S/(ld)(mid+1));
	}
	if(k>=i) {
		ans = min(ans, dp[i][mid]+pd[i+1][k-i]/(ld)(mid+1));
	}
	}
	ans = min(ans, pd[1][k]);
	return ans;
}

int main () {
	ios_base::sync_with_stdio(false), cin.tie(0);
	cout<<fixed<<setprecision(10);

	cin>>n>>k;
	for(int i=1; i<=n; i++) {
		cin>>A[i]>>B[i];
		if(B[i]==-1) B[i] = 1000000;
		x[i] = {B[i], A[i]};
	}

	sort(x+1, x+n+1);

	for(int i=1; i<=n+1; i++) fill(pd[i], pd[i]+k+2, 1e9);
	pd[n+1][0] = 0;
	for(int i=n; i>=1; i--) {
		for(int j=0; j<=k; j++) {
			pd[i][j] = pd[i+1][j];
			if(j > 0) pd[i][j] = min(pd[i][j], pd[i+1][j-1] + x[i].S);
		}
	}

	ld res = 1e9;
	/*
	int l=0, r=k;
	while(r-l>1) {
		int mid = (l+r)/2;
		if(check(mid) > check(mid+1)) {
			res=min(res, check(mid+1));
			l=mid;
		} else {
			res=min(res, check(mid));
			r=mid;
		}
	}
	*/
	for(int i=0; i<=k; i++) res = min(res, check(i));

	cout<<res;

	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