BOJ2110 공유기 설치 (매개변수 탐색)

https://www.acmicpc.net/problem/2110

2110번: 공유기 설치

import java.util.*;
import java.io.*;

public class Main
{
    public static int n;
    public static int m;
    public static Integer[] houses;


    public static boolean check(int dist){
        int count =1;
        int cur = houses[0];
        
        for(int i =1; i<n; i++){
            if(cur+dist > houses[i]) {
                continue;
            }else{
                count++;
                cur = houses[i];
            }
                
        }
        if(count>=m) {
            return true;
        }else{
            return false;
        }
    }
	public static void main(String[] args) throws IOException {
	    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	    
	    String[] input1 = br.readLine().split(" ");
	    
	    n = Integer.valueOf(input1[0]);
	    m = Integer.valueOf(input1[1]);
		houses = new Integer[n];
		
		for(int i=0; i<n;i++){
		    houses[i] = Integer.valueOf(br.readLine());
		}
		Arrays.sort(houses);
		
		int l = 0;
		int r = 1_000_000_000;
		int ans = 0;
		while(l<=r){
		    int mid  = (l+r)/2;
		    if(check(mid)){
		        l = mid + 1;
		        ans = mid;
		    }else{
		        r = mid - 1;
		    }
		}
        
        
        System.out.println(ans);
		
	}
}

import java.util.Arrays;
import java.util.Scanner;

class Main
{
    static int calculateCount(int[] xs, int distance) {
        int pastX = xs[0];
        int cnt = 1;
        for (int i = 1; i < xs.length; i++)
            if (xs[i] - pastX >= distance) {
                pastX = xs[i];
                cnt++;
            }
        return cnt;
    }

    public static void main (String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int C = sc.nextInt();
        int[] xs = new int[N];
        for (int i = 0; i < N; i++)
            xs[i] = sc.nextInt();

        Arrays.sort(xs);

        int l = 1, r = xs[N - 1] - xs[0], ans = -1;
        while (l <= r) {
            int m = (l + r) / 2;
            if (calculateCount(xs, m) >= C) {
                ans = m;
                l = m + 1;
            }
            else r = m - 1;
        }
        System.out.println(ans);
    }
}