[백준 JAVA] 2805번: 나무 자르기

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

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.StringTokenizer;

public class Main {
	public static int N, M;
	public static long MAX = 0;
	public static int[] arr;

	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer(br.readLine());
		N = Integer.parseInt(st.nextToken());
		M = Integer.parseInt(st.nextToken());

		arr = new int[N];
		
		st = new StringTokenizer(br.readLine());
		for (int i = 0; i < N; i++) {
			arr[i] = Integer.parseInt(st.nextToken());
			if (MAX < arr[i]) {
				MAX = arr[i];
			}
		}
		
		
		bs(arr);

	}

	public static void bs(int[] arr) {
		long lo = 0;
		long hi = MAX;
		while (lo < hi) {
			long mid = (lo + hi) / 2;

			long cnt = 0;

			for (int i = 0; i < arr.length; i++) {
				if(arr[i] - mid > 0)
					cnt += (arr[i] - mid);
			}

			if (cnt < M) {
				hi = mid;
			} else {
				lo = mid + 1;
			}

			
		}
		System.out.println(lo-1);
	}
}