Interleave Lists - codepath/compsci_guides GitHub Wiki

Unit 3 Session 2 (Click for link to problem statements)

U-nderstand

Understand what the interviewer is asking for by using test cases and questions about the problem.

P-lan

Plan the solution with appropriate visualizations and pseudocode.

General Idea: Loop from 0 to the longer length, and if valid, add an element from each list at that index,

1) Create an empty list for results
2) Find the length of the longer list
3) For each index from 0 to the longer length:
  a) If index is valid in lst1, add that element to results
  b) If index is valid in lst2, add that element to results
4) Return the results list

⚠️ Common Mistakes

• You might be tempted to write two different versions of the same code, one for when lst1 > lst2, and one for the opposite. Try to think of a way to write one block of code that works in both cases!

I-mplement

def interleave_lists(lst1, lst2):
    result = []
    
    lst1_len = len(lst1)
    lst2_len = len(lst2)
    length_of_longest_list = max(lst1_len, lst2_len)
	  
    for i in range(length_of_longest_list):
        if i < lst1_len:
            result.append(lst1[i])
        if i < lst2_len:
            result.append(lst2[i])
    return result