Search insert position

Given a sorted array and a target value, return the index if the target is found. 
If not, return the index where it would be if it were inserted in order.

You may assume NO duplicates in the array.

Have you met this question in a real interview? Yes
Example
[1,3,5,6], 5 → 2

[1,3,5,6], 2 → 1

[1,3,5,6], 7 → 4

[1,3,5,6], 0 → 0

Challenge 
O(log(n)) time

Tags 
Sorted Array Array Binary Search

public int searchInsert(int[] A, int target) {
        // write your code here
        // int ans;
        if (A == null || A.length == 0){
            return 0;
        } /*else if (target < A[0]) {
            return 0;
        }*/
            
        int start = 0, end = A.length - 1;
        
        while (start + 1 < end) {
            int mid = start + (end - start) / 2;
            if (A[mid] == target){
                return mid;
            } else if (A[mid] < target) {
                start = mid;
            } else {
                end = mid;
            }
        }
        
        if (A[start] >= target) {
            return start;
        } else if (A[end] >= target) {
            return end;
        
        } else {
            return end + 1;
        } 
    }