华为OD机试-最佳植树距离-二分（JAVA 2025A卷）

import java.util.*;
/**
 * @version Ver 1.0
 * @date 2025/6/19
 * @description 最小种植距离
 */
public class MinPlantDistance {
    public static void main(String[] args) {
        Scanner sc =new Scanner(System.in);
        int num = Integer.parseInt(sc.nextLine());
        int[] arrs = Arrays.stream(sc.nextLine().split("\\s+")).mapToInt(Integer::parseInt).toArray();
        int target = Integer.parseInt(sc.nextLine());
        solve(arrs, target);
    }

    private static void solve(int[] arrs, int target) {
        Arrays.sort(arrs);
        int left =1, right = Arrays.stream(arrs).max().getAsInt() - Arrays.stream(arrs).min().getAsInt();

        while(left < right){
            int mid = left + (right - left+1) / 2;//向上取整
            if(canReach(arrs,target,mid)){
                left = mid;
            }else{
                right = mid-1;
            }
        }
        System.out.println(left);
    }

    private static boolean canReach(int[] arrs, int target, int mid) {
        // mid 最小间距, a 存放前一个比较元素的索引 count 已经种树的数量，因为已经排序，默认从最小的位置开始种树
        int a = 0, count = 1;
        for (int i = 1; i < arrs.length; i++) {
            if(arrs[i] - arrs[a] >= mid){
                count++;
                a = i;
            }
        }
        return count >= target;
    }
}