Leetcode1313-Decompress Run-Length Encoded List.js

/**
 * https://leetcode.com/problems/decompress-run-length-encoded-list/description/
 * Difficulty:Easy
 *
We are given a list nums of integers representing a list compressed with run-length encoding.
Consider each adjacent pair of elements [freq, val] = [nums[2*i], nums[2*i+1]] (with i >= 0).  For each such pair, there are freq elements with value val concatenated in a sublist. Concatenate all the sublists from left to right to generate the decompressed list.
Return the decompressed list.


Example 1:

Input: nums = [1,2,3,4]
Output: [2,4,4,4]
Explanation: The first pair [1,2] means we have freq = 1 and val = 2 so we generate the array [2].
The second pair [3,4] means we have freq = 3 and val = 4 so we generate [4,4,4].
At the end the concatenation [2] + [4,4,4] is [2,4,4,4].
Example 2:

Input: nums = [1,1,2,3]
Output: [1,3,3]


/**
 * @param {number[]} nums
 * @return {number[]}
 */
var decompressRLElist = function(nums) {
    
let result = []
let freq = 0; 
let len = nums.length
for (var i = 0; i< len; i = i + 2) { 
  while(freq < nums[i]) { // push value correct number of times
    result.push(nums[i+1]);
    freq++;
  }
  freq = 0; // clear frequency every iteration
}

return result
};