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Count the Number of Lines in Input

Certification: Basic Level Accuracy: 70% Submissions: 20 Points: 10

Write a C++ program that counts the number of lines in the input. The program should take input from the user and return the number of lines.

Example 1
     
  • Input: string = "Hello\nWorld\nC++"
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  • Output: 3
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  • Explanation: 
       
    • Step 1: Initialize a line counter to 1 (assuming at least one line exists).
      •  
    • Step 2: Initialize a pointer to the start of the input string.
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    • Step 3: Iterate through each character of the string using the pointer.
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    • Step 4: For each character, check if it's a newline character ('\n').
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    • Step 5: If a newline character is found, increment the line counter.
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    • Step 6: Return the line count (3 lines).
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    •
Example 2
     
  • Input: string = "One\nTwo\nThree\nFour\nFive"
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  • Output: 5
    •  
  • Explanation: 
       
    • Step 1: Initialize a line counter to 1 (assuming at least one line exists).
      •  
    • Step 2: Initialize a pointer to the start of the input string.
      •  
    • Step 3: Iterate through each character of the string using the pointer.
      •  
    • Step 4: For each character, check if it's a newline character ('\n').
      •  
    • Step 5: If a newline character is found, increment the line counter.
      •  
    • Step 6: Return the line count (5 lines).
      •  
    •
Constraints
     
  • Input size ≤ 10^6 characters
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  • Input contains printable ASCII characters
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  • Time Complexity: O(n) where n is the number of characters in the input
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  • Space Complexity: O(1)
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StringsFunctions / MethodsFile Handling IBMSamsung
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Hint
Solution

Solution Hints

    
  
  • Use string stream to handle input instead of file handling.
    • 
  
  • Count the number of newline characters in the input.
    • 
  
  • Return the count as the number of lines.
    •

Steps to solve by this approach:

 Step 1: Define a function countLines that takes a constant string reference as parameter.

 Step 2: Create an input string stream with the provided string.

 Step 3: Initialize a line counter to zero.

 Step 4: Use getline in a while loop to read each line from the stream.

 Step 5: Increment the line counter for each successful read.

 Step 6: Return the final line count.

 Step 7: In main, prompt the user to enter multi-line content.

 Step 8: Read all input lines into a string, appending a newline after each line.

 Step 9: Call countLines with the full input string and print the result.

Submitted Code :