Description
We are given a list nums
of integers representing a list compressed with run-length encoding.
Consider each adjacent pairย of elements [freq, val] = [nums[2*i], nums[2*i+1]]
ย (with i >= 0
).ย 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.
ย
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]
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Constraints:
2 <= nums.length <= 100
nums.length % 2 == 0
1 <= nums[i] <= 100
Solution
Python3
class Solution:
def decompressRLElist(self, nums: List[int]) -> List[int]:
res = []
n = len(nums)
for i in range(0,n,2):
for _ in range(nums[i]):
res.append(nums[i+1])
return res