C++ Exercises: Create a new string of the characters at indexes 0,1, 4,5, 8,9 ... from a given string

Last update on April 07 2025 12:56:51 (UTC/GMT +8 hours)

Characters at Index 0, 1, 4, 5, ...

Write a C++ program to create the string of the characters at indexes 0,1,4,5,8,9 ... from a given string.

Sample Solution:

C++ Code :

#include <iostream>
using namespace std;

// Function to process a string in chunks and concatenate substrings
string test(string str1)
{
    string result = "";

    // Loop through the string in increments of 4 characters
    for (int i = 0; i < str1.length(); i += 4)
    {
        int c = i + 2; // Calculate the index 'c'

        int n = 0;
        n += c > str1.length() ? 1 : 2; // Determine the length of the substring

        // Append the substring of length 'n' to the 'result' string
        result += str1.substr(i, n);
    }
    return result; // Return the processed string
}

int main() 
{
    // Test cases to process strings in chunks and concatenate substrings
    cout << test("Python") << endl;
    cout << test("JavaScript") << endl; 
    cout << test("HTML") << endl; 

    return 0; // Return 0 to indicate successful completion
}

Sample Output:

Pyon
JaScpt
HT 

Visual Presentation:

Flowchart:

For more Practice: Solve these Related Problems:

• Write a C++ program to extract characters from an input string at indices 0, 1, 4, 5, 8, 9, etc., and form a new string.
• Write a C++ program that reads a string and outputs a new string composed of characters at positions following the pattern: 0,1, then every 4th and 5th character.
• Write a C++ program to generate a patterned substring by picking characters from specific indexes (0, 1, 4, 5, 8, 9, ...) of the original string.
• Write a C++ program that processes a string and forms a new string using characters at predetermined indices that follow the given repeating pattern.

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