[백준] 31066 비 오는 날 - Greedy / Java

• 문제 링크

31066번: 비 오는 날

 

• 풀이 코드

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        StringBuilder sb = new StringBuilder();

        int t = read();
        while (t-- > 0) {
            int n = read(), m = read(), k = read();

            if (m == 1 && k == 1 && n > 1) {
                sb.append("-1\n");
                continue;
            }

            int cnt = -1;
            do {
                n -= m * k;
                cnt += 2;
            } while (n++ > 0);

            sb.append(cnt).append("\n");
        }

        bw.write(sb.toString());
        bw.flush();
    }

    private static int read() throws IOException {
        int c, n = System.in.read() & 15;
        while ((c = System.in.read()) > 32) n = (n << 3) + (n << 1) + (c & 15);

        return n;
    }

}