LintCode Search Insert Position

public class Solution {
    /** 
     * param A : an integer sorted array
     * param target :  an integer to be inserted
     * return : an integer
     */
    public int searchInsert(int[] A, int target) {
        if(A == null) return -1;
        if(A.length == 0) return 0;
        int left = 0; int right = A.length - 1;
        while(left + 1 < right){
            int mid = (left + right) / 2;
            if(A[mid] == target){
                return mid;
            }
            else if(A[mid] < target){
                left = mid;
            }
            else if(A[mid] > target){
                right = mid;
            }
        }
        if(A[left] >= target){
            return left;
        }
        else if(A[right] < target){
            return right + 1;
        }
        else return right;
    }
}