Squares of a Sorted Array

Given an array of integers A sorted in non-decreasing order, return an array of the squares of each number, also in sorted non-decreasing order.

 

Example 1:

Input: [-4,-1,0,3,10]
Output: [0,1,9,16,100]
Example 2:

Input: [-7,-3,2,3,11]
Output: [4,9,9,49,121]
 

Note:

  1. 1 <= A.length <= 10000
  2. -10000 <= A[i] <= 10000
  3. A is sorted in non-decreasing order.

Solution:

class Solution {
    public int[] sortedSquares(int[] A) {
        int n = A.length;
        int i = 0, j = n - 1;
        int[] res = new int[n];
        for (int k = n - 1; k >= 0; k --) {
            if (Math.abs(A[i]) > Math.abs(A[j])) {
                res[k] = A[i] * A[i];
                i ++;
            } else {
                res[k] = A[j] * A[j];
                j --;
            }
        }
        return res;
    }
}