[BOJ] 2805 나무 자르기 (JAVA)

https://www.acmicpc.net/problem/2805

2805번: 나무 자르기

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {
	
    public static void main(String[] args) throws Exception {

        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());
        long[] input = new long[N];
        long l = 0;
        long r = 0;
        st = new StringTokenizer(br.readLine(), " ");
        for (int i = 0; i < N; i++) {
            input[i] = Long.parseLong(st.nextToken());
            if (r < input[i]) r = input[i];
        }

        while (l < r) {
            long m = (l + r) >> 1;
            long sum = 0;

            for (int i = 0; i < N; i++) {
                if (m < input[i]) sum += input[i] - m;
            }

            if (sum < K) r = m;
            else l = m + 1;
        }

        System.out.print(l - 1);

    }

}