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counter
hash table
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BinarySearch 0995 Equivalent Product Pairs
Problem statement
https://binarysearch.com/problems/Equivalent-Product-Pairs/
Solution
Notice that all valuea are unique. Then we can keep counter of all products.
Complexity
It is O(n^2)
for time and space.
Code
class Solution:
def solve(self, A):
cnt = Counter(x*y for x, y in combinations(A, 2))
return sum(c * (c - 1) * 4 for c in cnt.values())