Decompress Run-Length Encoded List

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My Thoughts

What Went Well
I solved the problem quickly and learned unique ways to solve this problem using operations I had never seen before. I also learned about the run-length encoding algorithm.

Solution Statistics

Time Spent Coding
2 minutes

Time Complexity
O(n * k) - We are taking n as the number of elements in the input list and k as the number of elements in the list being appended to ret. The extend function iterates through the list being appended to the ret list, resulting in the O(n * k) time complexity since this occurs in each loop.

Space Complexity
O(n * k) - We store each 2nd element from the input list k times in the ret list, resulting in the O(n * k) space complexity.

Runtime Beats
73.79% of other submissions

Memory Beats
96.37% of other sumbissions

Solution

class Solution(object):
    def decompressRLElist(self, nums):
        ret = []

        # Each iteration, we are accessing two elements, we must
        # increment through the list by two elements at a time
        for i in range(0,len(nums),2):
            # val = nums[i+1]
            # frquency = nums[i]
            ret.extend([nums[i+1]]*nums[i])

        return ret