Data Structures and Algorithms in Python/

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Solution Review: Pairs with Sums

Solution Review: Pairs with Sums

This lesson contains the solution review for the challenge of finding pairs in a doubly linked list which sum up to the given number.

We'll cover the following...

Here is an overview of our solution to finding a pair of nodes in a doubly linked list that sums up to a specific number.

Implementation

Here is the coding solution in Python for the previous challenge:

Python 3.5
def pairs_with_sum(self, sum_val):
  pairs = list()
  p = self.head 
  q = None 
  while p:
    q = p.next
    while q:
      if p.data + q.data == sum_val:
          pairs.append("(" + str(p.data) + "," + str(q.data) + ")")
      q = q.next
    p = p.next
  return pairs

Explanation

On line 2, pairs is initialized to an empty Python list. In the next lines (lines 3-4), p and q are set equal to self.head ...