Python List Comprehension to find pair with given sum from two arrays

Given two unsorted arrays of distinct elements, the task is to find all pairs from both arrays whose sum is equal to x.

Examples:

Input :  arr1 = [-1, -2, 4, -6, 5, 7]
         arr2 = [6, 3, 4, 0]  
         x = 8
Output : [(5, 3), (4, 4)]
         

Input : arr1 = [1, 2, 4, 5, 7] 
        arr2 = [5, 6, 3, 4, 8]  
        x = 9
Output : [(1, 8), (4, 5), (5, 4)]



We have existing solution for this problem please refer Given two unsorted arrays, find all pairs whose sum is x link. We can solve this problem quickly in python using List comprehension. Approach is very simple, we will consider all those pairs for which if k lies in arr2 then x-k should lie in arr1, so pair will be (x-k,k).

filter_none

edit
close

play_arrow

link
brightness_4
code

# Function to find all pairs whose sum is x in 
# two arrays
  
def allPairs(arr1,arr2,x):
       
     # finds all pairs in two arrays
     # whose sum is x
     print ([(x-k,k) for k in arr2 if (x-k) in arr1])
  
# Driver program
if __name__ == "__main__":
    arr1 = [-1, -2, 4, -6, 5, 7]
    arr2 = [6, 3, 4, 0]  
    x = 8
    allPairs(arr1,arr2,x)

chevron_right


Complexity : O(n*n)
Output:

[(5, 3), (4, 4)]


My Personal Notes arrow_drop_up

Experienced Software Engineer with a demonstrated history of working in the information technology and services industry Skilled in Big Data technologies, Data Structures, Algorithm, Software Development, App Development, Databases, Python, Java, C, and WordPress

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.