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Concatenate Two Strings

Certification: Basic Level Accuracy: 64.71% Submissions: 17 Points: 10

Write a C++ program that concatenates two strings without using the `strcat()` function.

Example 1
    
  
  • Input: string1 = "Hello", string2 = "World"
    • 
  
  • Output: "HelloWorld"
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  • Explanation:
    
      
      
    • Step 1: Create a new string with size equal to the sum of lengths of both input strings.
      • 
      
    • Step 2: Copy characters from the first string to the new string.
      • 
      
    • Step 3: Append characters from the second string to the new string.
      • 
      
    • Step 4: Return the concatenated string.
      • 
    
    
  
    •
Example 2
    
  
  • Input: string1 = "C++", string2 = "Programming"
    • 
  
  • Output: "C++Programming"
    • 
  
  • Explanation:
    
      
      
    • Step 1: Create a new string with size equal to the sum of lengths of both input strings.
      • 
      
    • Step 2: Copy characters from the first string to the new string.
      • 
      
    • Step 3: Append characters from the second string to the new string.
      • 
      
    • Step 4: Return the concatenated string.
      • 
    
    
  
    •
Constraints
    
  
  • 1 ≤ len(string1), len(string2) ≤ 10^6
    • 
  
  • The strings contain printable ASCII characters.
    • 
  
  • Time Complexity: O(n + m), where n and m are the lengths of the two strings
    • 
  
  • Space Complexity: O(n + m)
    •
StringsFunctions / MethodsAccentureAirbnb
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Hint
Solution

Solution Hints

    
  
  • Create a new string with enough space to hold both strings.
    • 
  
  • Copy the characters of the first string into the new string.
    • 
  
  • Append the characters of the second string to the new string.
    •

Steps to solve by this approach:

 Step 1: Define a function concatenateStrings that takes a destination character array and a source character pointer.
 Step 2: Initialize two index variables to track positions in both strings.
 Step 3: Find the end of the destination string by locating the null terminator.
 Step 4: Copy characters from source to destination one by one until the source's null terminator.
 Step 5: Add a null terminator at the end of the concatenated string.
 Step 6: In main, call concatenateStrings with two strings and print the result.

Submitted Code :