关于java:求解非递减数组范围下标

题目

有序非递加数组，找出在指定区间中的元素地位，输入起始和完结地位的下标。
如数组： 1,2,2,3,4,6
区间:2,8(大于等于2，小于等于8)
后果1,5（1是合乎区间最右边的下标，5是合乎区间最左边的下标）
要求工夫复杂度要小于O(N)(不能够是O(N))

解法1:二分查找

private int[] array = {1,2,2,3,4,6};private int min = -20;private int max = 8;public void binarySearch() {    int left = binarySearch(array,min,true);    int right = binarySearch(array,max,false);    System.out.println(left +" "+ right);}private int binarySearch(int[] array,int target,boolean first){    int length = array.length;    if (length == 0) {        return -1;    }    if (array[0] > max) {        return -1;    }    if (array[length-1] < min) {        return -1;    }    int left = 0,right = length -1;    while (left <= right) {        int mid = left + (right -left)/2;        if (array[mid] > target) {            right = mid - 1;        }else if (array[mid] < target) {            left = mid + 1;        }else {            if (first) {                if (mid == 0 || array[mid - 1] != target) {                    return mid;                } else {                    right = mid - 1;                }            } else {                if (mid == 0 || array[mid + 1] != target) {                    return mid;                } else {                    left = mid + 1;                }            }        }    }    if (first) {        return left;    } else {        return right;    }}

github源码

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