1. What I learned

    Create a list with a repeated number when I know the length of a list

        Write a number in a []. Multiply it by the length of the list.
        ex) numList = [5]*3
        –> numList = [5,5,5]

2. How I sloved

    I made a list and repeated ‘nums//2’ to make the final list. Because the list had a pattern that odd numbers were the frequency of even numbers. Then I concatenated the even numbers to the ‘result’ list as many odd numbers.

3. Code

class Solution:
    def decompressRLElist(self, nums):
        result = []
        for i in range(0,len(nums)//2):
            result += [nums[2*i+1]] * nums[2*i]
        return result

4. Result

        Runtime : 64 ms(87.63%), Memory usage : 13.3 MB(100.00%)
        (Runtime can be different by a system even if it is a same code.)

Check out the my GitHub repo for more info on the code. If you have questions, you can leave a reply on this post.