Lecture 132:- Reversing a String

Reversing a string means reversing the order of characters in the string. There are various ways to achieve this, and here are two common approaches in C++:

1. Using In-Place Reversal: In this method, you can swap the characters from the beginning and end of the string, moving towards the center until the entire string is reversed.
2. Using the Standard Library: You can use the std::reverse function from the <algorithm> header provided by the C++ Standard Library, which performs the string reversal for you.

Here's how you can implement both approaches:

In-Place Reversal:

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#include <iostream> #include <string> void reverseStringInPlace(std::string& str) {    int left = 0;    int right = str.length() - 1;    while (left < right) {        std::swap(str[left], str[right]);        left++;        right--;    } } int main() {    std::string inputString;    std::cout << "Enter a string: ";    std::getline(std::cin, inputString);    reverseStringInPlace(inputString);    std::cout << "Reversed string: " << inputString << std::endl;    return 0; }

Using Standard Library:

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#include <iostream> #include <string> #include <algorithm> int main() {    std::string inputString;    std::cout << "Enter a string: ";    std::getline(std::cin, inputString);    std::reverse(inputString.begin(), inputString.end());    std::cout << "Reversed string: " << inputString << std::endl;    return 0; }

Both programs will reverse the input string and display the result.

Sample Input:

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Enter a string: Hello, World!

Sample Output:

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Reversed string: !dlroW ,olleH

Choose the method that best suits your needs. The in-place reversal can be more efficient if you are concerned about memory usage, but using the standard library function is more concise and easier to read.