백준 - 물병 1052

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1. 전체 소스

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
 
public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
 
        StringTokenizer st = new StringTokenizer(br.readLine());
        int N = Integer.parseInt(st.nextToken());
        int K = Integer.parseInt(st.nextToken());
 
        int rst = buyBottle(N, K);
        System.out.println(rst);
        br.close();
    }
 
    private static int buyBottle(int n, int k) {
        if(n <= k) return 0;
 
        int iterations = k - 1;
        int pow2 = 1;
        while (pow2 < n) {
            pow2 *= 2;
        }
 
        while (iterations > 0) {
            pow2 /= 2;
            n -= pow2;
            if(n == 0) return 0;
            iterations--;
        }
 
        pow2 /= 2;
        return pow2 - n;
    }
}JAVA

 

 

 

 

 

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https://www.acmicpc.net/problem/1052

1052번: 물병