SortSquares.java

package Array;

import java.util.Arrays;

public class SortSquares {

    /**
     * @param a - It is the array which has -ve to +ve values.
     * @return - It returns the ans array in which squares are sorted.
     */
    static int[] sortedSquares(int[] a) {
        int n = a.length, i = 0, j = n - 1, k = 0;
        int[] ans = new int[n];

        while (i <= j) {
            if (Math.abs(a[i]) < Math.abs(a[j])) {
                a[j] *= a[j];
                ans[k++] = (a[j--]);
            } else {
                a[i] *= a[i];
                ans[k++] = (a[i++]);
            }
        }
        reverse(ans);
        return ans;
    }

    static void reverse(int[] a) {
        int temp, i = 0, j = a.length - 1;
        while (i < j) {
            temp = a[i];
            a[i] = a[j];
            a[j] = temp;
            i++;
            j--;
        }
    }

    // Time Complexity - O(n), Auxiliary Space - O(n)
    public static void main(String[] args) {

        int[] a = {-10, -3, 2, 5, 6};
        int[] ans = sortedSquares(a);
        System.out.println(Arrays.toString(ans));
    }
}