Submission #15352

#	Time	Username	Problem	Language	Result	Execution time	Memory
15352		cki86201	맛있는 과자 (kriii3_A)	C++98	33 / 33	0 ms	1212 KiB

A

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<math.h>
#include<algorithm>
using namespace std;

typedef long long ll;

ll C[50][50];

int main(){
	int a, b, n;
	ll K;
	scanf("%d%d%d%lld", &a, &b, &n, &K);
	C[0][0] = 1;
	for (int i = 1; i <= 42; i++){
		C[i][0] = 1;
		for (int j = 1; j <= i; j++){
			C[i][j] = C[i - 1][j - 1] + C[i - 1][j];
		}
	}
	ll now = 0;
	if (a > b)swap(a, b);
	for (int i = 0; i <= n; i++){
		now += C[n][i];
		if (now >= K){
			printf("%.10f\n", log(a * b / 2.0) + 2 * (log(a) * i + log(b) * (n - i)) - n * log(a * a + b * b));
			break;
		}
	}
	return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 23 / 23