Number of Ways Where Square of Number Is Equal to Product of Two Numbers.py

# Runtime: 753 ms (Top 50.00%) | Memory: 14 MB (Top 47.37%)
class Solution:
    def numTriplets(self, nums1: List[int], nums2: List[int]) -> int:
        sqr1, sqr2 = defaultdict(int), defaultdict(int)
        m, n = len(nums1), len(nums2)
        for i in range(m):
            sqr1[nums1[i]**2] += 1
        for j in range(n):
            sqr2[nums2[j]**2] += 1

        res = 0
        for i in range(m-1):
            for j in range(i+1, m):
                if nums1[i]*nums1[j] in sqr2:
                    res += sqr2[nums1[i]*nums1[j]]

        for i in range(n-1):
            for j in range(i+1, n):
                if nums2[i]*nums2[j] in sqr1:
                    res += sqr1[nums2[i]*nums2[j]]
        return res