Leetcode - Decompress Run-Length Encoded List Solution
Poor Man
- Published
- Updated
- Reading time
- 1 min read
- Length
- 188 words
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:
Text
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:
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Input: nums = [1,1,2,3]
Output: [1,3,3]Constraints:
2 <= nums.length <= 100nums.length % 2 == 01 <= nums[i] <= 100
Solution in Python#
Python
class Solution:
def decompressRLElist(self, nums: List[int]) -> List[int]:
output = []
for i in range(0,len(nums)-1,2):
output.extend([nums[i+1]]*nums[i])
return output