Submission #15205

#	Time	Username	Problem	Language	Result	Execution time	Memory
15205		tonyjjw	맛있는 과자 (kriii3_A)	C++98	33 / 33	0 ms	1224 KiB

A

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <vector>
#include <algorithm>
using namespace std;

int a, b, n;
long long k;

long long c[64][64];

int main(void) {
    c[0][0] = 1;
    for (int i = 1; i < 64; i++) {
        c[i][0] = 1;
        for (int j = 1; j <= i; j++) {
            c[i][j] = c[i-1][j-1] + c[i-1][j];
        }
    }
    scanf("%d %d %d %lld", &a, &b, &n, &k);
    double area = log((double) a * b / 2.);
    if (a == b) {
        printf("%.10lf\n", (double) n * log(0.5) + area);
    } else {
        if (a < b) swap(a, b);
        long long rank_sum = 0;
        double ans = 0.0;
        double ra = (double)a * a / (a * a + b * b);
        double rb = (double)b * b / (a * a + b * b);
        for (int i = 0; i <= n; i++) {
            rank_sum += c[n][i];
            if (rank_sum >= k) {
                ans = (double) (n-i) * log(ra) + i * log(rb) + area;
                break;
            }
        }
        printf("%.10lf\n", ans);
    }
    return 0;
}

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