1313. Decompress Run-Length Encoded List

We are given a list nums of integers representing a list compressed with run-length encoding.

Consider each adjacent pair of elements [a, b] = [nums[2*i], nums[2*i+1]] (with i >= 0).  For each such pair, there are a elements with value b in the decompressed list.

Return the decompressed list.

Example 1:

Input: nums = [1,2,3,4]
Output: [2,4,4,4]

Constraints:

• 2 <= nums.length <= 100
• nums.length % 2 == 0
• 1 <= nums[i] <= 100