[LeetCode]35 Search Insert Position

https://oj.leetcode.com/problems/search-insert-position/

http://fisherlei.blogspot.com/2013/01/leetcode-search-insert-position.html

public class Solution {
    public int searchInsert(int[] A, int target) {
        
        if (A == null)
            return -1;  // invalid num
            
        if (A.length == 0)
            return 0;   // empty array, no need to search.
     
        return search(A, target, 0, A.length - 1);       
    }
    
    private int search(int[] A, int target, int low, int high)
    {
        if (low > high)
            return -1;
        
        if (low == high)
        {
            if (A[low] >= target)
                return low;
            else
                return low + 1;
        }
        
        int mid = (low + high) / 2;
        
        if (A[mid] == target)
            return mid;
        else if (A[mid] > target)
            return search(A, target, low, mid);
        else
            return search(A, target, mid + 1, high);    // How to divide the array.
    }
}