Search Insert Position

Search Insert Position.java

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.

Here are few examples.
[1,3,5,6], 5 → 2
[1,3,5,6], 2 → 1
[1,3,5,6], 7 → 4
[1,3,5,6], 0 → 0

Time Complexity: O(lgn)

public class Solution {
    public int searchInsert(int[] A, int target) {
        // Start typing your Java solution below
        // DO NOT write main() function
        if (A==null||0==A.length) return 0;
        
        int start=0;
        int end=A.length-1;
        while (start<=end){
            int mid=(start+end)/2;
            if (A[mid]==target){
                return mid;
            }
            else if (A[mid]>target){
                end=mid-1;
            }
            else{
                
                start=mid+1;
            }
        }                
        return start;
    }
}