腾讯云算法面试题-给定边界输出对应索引下标

给出有序数组(非递减)和闭区间, 找出数组中在区间之内的元素起始位置和结束位置
* 输入：
* 1. 有序数组[1,1,2,3,4,5,5]
* 2. 闭区间[-3,3]
* 输出：[0,3]
* 解释：在数组中，前4个元素在区间之内，则起始位置为0，结束位置为3
* 要求：最坏情况时间复杂度小于O(n)

public class TxTest {

    public static void main(String[] args) {
        int[] arrays = {-10, 1, 2, 3, 4, 5, 5};
        fun1(arrays, -3, 3);
    }

    public static void fun1(int[] arrays, int start, int end) {
        int startIndex = startBound(arrays, start);
        int endIndex = endBound(arrays, end);
        System.out.println("[" + startIndex + "," + endIndex + "]");
    }

    private static int startBound(int[] arrays, int key) {
        int start = 0;
        int last = arrays.length;
        while (start < last) {
            int mid = (start + last) / 2;
            if (arrays[mid] >= key) {
                last = mid;
            } else {
                start = mid + 1;
            }
        }
        return start;
    }

    private static int endBound(int[] arrays, int key) {
        int start = 0;
        int last = arrays.length;
        while (start < last) {
            int mid = (start + last) / 2;
            if (arrays[mid] <= key) {
                start = mid + 1;
            } else {
                last = mid;
            }
        }
        return start - 1;