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Merge Two Sorted Lists into a Single Sorted List

Certification: Basic Level Accuracy: 24.74% Submissions: 97 Points: 10

Write a Python program that merges two sorted lists of integers into a single sorted list.

Example 1
    

  • Input: list1 = [1, 3, 5, 7], list2 = [2, 4, 6, 8]
    • 

  • Output: [1, 2, 3, 4, 5, 6, 7, 8]
    • 

  • Explanation: 
      

    • Step 1: Initialize two pointers, one for each list.
      • 

    • Step 2: Compare elements at current pointers and add the smaller one to result.
      • 

    • Step 3: Move the pointer for the list whose element was just added.
      • 

    • Step 4: Repeat until all elements from both lists are processed.
      • 

    • Step 5: Return the merged sorted list.
      • 

    •
Example 2
    

  • Input: list1 = [10, 20, 30], list2 = [5, 15, 25]
    • 

  • Output: [5, 10, 15, 20, 25, 30]
    • 

  • Explanation: 
      

    • Step 1: Initialize two pointers, one for each list.
      • 

    • Step 2: Compare elements at current pointers and add the smaller one to result.
      • 

    • Step 3: Move the pointer for the list whose element was just added.
      • 

    • Step 4: Repeat until all elements from both lists are processed.
      • 

    • Step 5: Return the merged sorted list.
      • 

    •
Constraints
    

  • 0 ≤ len(list1), len(list2) ≤ 10^5
    • 

  • Both input lists are already sorted in ascending order
    • 

  • Time Complexity: O(n+m) where n and m are the lengths of the input lists
    • 

  • Space Complexity: O(n+m) for storing the result
    •
ArraysFunctions / MethodsPointers and ReferencesEYSnowflake
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Hint
Solution

Solution Hints

    
  
  • Use two pointers, one for each list, and compare elements
    • 
  
  • Built-in sorted() function: return sorted(list1 + list2)
    • 
  
  • Merge sort approach: compare elements from both lists and append the smaller one to the result
    •

Steps to solve by this approach:

 Step 1: Initialize an empty result list and pointers for both input lists.
 Step 2: Compare elements from both lists while both pointers are within bounds.
 Step 3: Add the smaller element to the result list and increment its pointer.
 Step 4: After one list is exhausted, append any remaining elements from the first list.
 Step 5: Append any remaining elements from the second list.
 Step 6: Return the merged sorted list.

Submitted Code :