977-squares-of-a-sorted-array.js

/**

Given an integer array nums sorted in non-decreasing order, return an array of the squares of each number sorted in non-decreasing order.

 

Example 1:

Input: nums = [-4,-1,0,3,10]
Output: [0,1,9,16,100]
Explanation: After squaring, the array becomes [16,1,0,9,100].
After sorting, it becomes [0,1,9,16,100].
Example 2:

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

Constraints:

1 <= nums.length <= 104
-104 <= nums[i] <= 104
nums is sorted in non-decreasing order.
 

Follow up: Squaring each element and sorting the new array is very trivial, could you find an O(n) solution using a different approach?

**/

/**
 * @param {number[]} nums
 * @return {number[]}
 */
var sortedSquares = function(nums) {
   
  const out = {};
  const res = [];
    
  for (let i = 0; i < nums.length; i++ ) {
      let square = nums[i] * nums[i];      
      if (typeof out[square] == 'undefined') {
          out[square] = 1;
      } else {
          out[square]++;
      }
  }
    
    
  for (let key in out) {
     for (let i = 0; i < out[key]; i++) {
         res.push(key);
     }
  } 
    
  return res
                                    
                                    
};