Submission #462307

#	Time	Username	Problem	Language	Result	Execution time	Memory
462307		grt	새로운 문제 (COCI19_akvizna)	C++17	65 / 130	243 ms	3520 KiB

Main

#include <bits/stdc++.h>
#define PB push_back
#define ST first
#define ND second
#define _ ios_base::sync_with_stdio(0); cin.tie(0);
//mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

using namespace std;

using ll = long long;
using pi = pair<int,int>;
using vi = vector<int>;


const int nax = 100 * 1000 + 10;
int n, k;
long double dp[nax];
int cnt[nax];

struct Line {
	long double a, b;
	int id;
	long double intersect(Line &he) {
		return (b - he.b) / (he.a - a);
	}
	long double eval(int x) {
		return a * x + b;
	}
};

deque<Line>lines;

int main() {_
	cin >> n >> k;
	long double low = 0.0, high = 1.0000, mid;
	for(int rep = 0; rep < 30; ++rep) {
		mid = (low + high) / 2.0;
		while((int)lines.size() > 0) lines.pop_back();
		for(int used = 0; used <= n; ++used) {
			dp[used] = 0;
			cnt[used] = 0;
			while((int)lines.size() > 1 && lines[0].eval(used - n) <= lines[1].eval(used - n)) {
				lines.pop_front();
			}
			long double res = 0.0;
			if((int)lines.size() > 0) {
				res = lines[0].eval(used - n) - mid;
				cnt[used] = cnt[lines[0].id] + 1;
			}
			dp[used] = max(dp[used], res);
			if(used < n) {
				Line l = {(long double)1/(n - used), dp[used] + 1.0, used};
				while((int)lines.size() > 1 && lines[(int)lines.size() - 2].intersect(l) <= lines[(int)lines.size() - 2].intersect(lines.back())) {
					lines.pop_back();
				}
				lines.push_back(l);
			}
		}
		if(cnt[n] <= k) {
			high = mid;
		} else {
			low = mid;
		}
	}
	mid = high;
	while((int)lines.size() > 0) lines.pop_back();
		for(int used = 0; used <= n; ++used) {
			dp[used] = 0;
			cnt[used] = 0;
			while((int)lines.size() > 1 && lines[0].eval(used - n) <= lines[1].eval(used - n)) {
				lines.pop_front();
			}
			long double res = 0.0;
			if((int)lines.size() > 0) {
				res = lines[0].eval(used - n) - mid;
				cnt[used] = cnt[lines[0].id] + 1;
			}
			dp[used] = max(dp[used], res);
			if(used < n) {
				Line l = {(long double)1/(n - used), dp[used] + 1.0, used};
				while((int)lines.size() > 1 && lines[(int)lines.size() - 2].intersect(l) <= lines[(int)lines.size() - 2].intersect(lines.back())) {
					lines.pop_back();
				}
				lines.push_back(l);
			}
		}
	cout << setprecision(10);
	cout << fixed;
	cout << dp[n] + mid * k;
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
• Subtask 6: 5 / 5
• Subtask 7: 5 / 5
• Subtask 8: 5 / 5
• Subtask 9: 5 / 5
• Subtask 10: 5 / 5
• Subtask 11: 5 / 5
• Subtask 12: 5 / 5
• Subtask 13: 5 / 5
• Subtask 14: 0 / 5
• Subtask 15: 0 / 5
• Subtask 16: 0 / 5
• Subtask 17: 0 / 5
• Subtask 18: 0 / 5
• Subtask 19: 0 / 5
• Subtask 20: 0 / 5
• Subtask 21: 0 / 5
• Subtask 22: 0 / 5
• Subtask 23: 0 / 5
• Subtask 24: 0 / 5
• Subtask 25: 0 / 5
• Subtask 26: 0 / 5