Divide array into equal pairs
October 30, 2022
array-and-hashmapProblem URL: Divide array into equal pairs
We can use a hashmap to store the frequency of each element in the array. Then we can iterate over the array and check if the frequency of the current element is even or not. If it is even, we can divide it by 2 and add it to the result. If it is odd, we can return false.
class Solution:
def divideArray(self, nums: List[int]) -> bool:
count = collections.Counter(nums)
for num in count.values():
if num % 2 != 0:
return False
return True
Time complexity: O(n)
Space complexity: O(n)