Search Insert Position

Problem

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.

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

Code - Java

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) {
        int low = 0;
        int high = A.length - 1;
        while (low <= high) {
            int mid = (low + high) / 2;
            if (A[mid] == target) {
                return mid;
            } else if (mid == 0 && A[mid] > target) {
                return mid;
            } else if (A[mid] > target && A[mid - 1] < target) {
                return mid;
            } else if (A[mid] < target) {
                low = mid + 1;
            } else {
                high = mid - 1;
            }
        }
        return A.length;
    }
}