Program to find tuple with same product in Python

Suppose we have an array nums with unique positive values, we have to find the number of tuples (a, b, c, d) such that a*b = c*d where a, b, c, and d are elements of nums, and all elements a, b, c and d are distinct.

So, if the input is like nums = [2,3,4,6], then the output will be 8 because we can get tuples like (2,6,3,4), (2,6,4,3), (6,2,3,4), (6,2,4,3), (3,4,2,6), (4,3,2,6), (3,4,6,2), (4,3,6,2).

To solve this, we will follow these steps −

• dic := an empty map, default value is 0 if some key is not present
• ans:= 0
• for i in range 0 to size of nums - 2, do
  • for j in range i+1 to size of nums, do
    • dic[nums[i]*nums[j]] := dic[nums[i]*nums[j]] + 1
• for each v in list of all values of dic, do
  • if v is same as 1, then
    • go for next iteration
  • v:= v-1
  • s:= (v/2) * (8+8*v)
  • ans := ans + s
• return ans as integer

Example

Let us see the following implementation to get better understanding −

from collections import defaultdict
def solve(nums):
   dic = defaultdict(int)
   ans=0
   for i in range(len(nums)-1):
      for j in range(i+1,len(nums)):
         dic[nums[i]*nums[j]]+=1
   for v in dic.values():
      if v==1:
         continue
      v=v-1
      s=(v/2) * (8+8*v)
      ans+=s
   return int(ans)

nums = [3,4,6,2]
print(solve(nums))

Input

[3,4,6,2]

Output

0