Example: In-Place String Reversal (Two Pointers) in C

// In-Place String Reversal (Two Pointers)
#include <stdio.h> // Required for printf

// Custom string length function
int get_string_length(char* str) {
    int length = 0;
    while (str[length] != '\0') {
        length++;
    }
    return length;
}

// Function to reverse a string in-place
void reverse_string_inplace(char* str) {
    int length = get_string_length(str);
    int start = 0;
    int end = length - 1;
    char temp; // Temporary variable for swapping

    while (start < end) {
        // Swap characters at start and end positions
        temp = str[start];
        str[start] = str[end];
        str[end] = temp;

        // Move pointers inward
        start++;
        end--;
    }
}

int main() {
    char myString[] = "programming"; // Modifiable string
    char anotherString[] = "hello world";

    printf("Original string 1: %s\n", myString);
    reverse_string_inplace(myString);
    printf("Reversed string 1: %s\n", myString);

    printf("\nOriginal string 2: %s\n", anotherString);
    reverse_string_inplace(anotherString);
    printf("Reversed string 2: %s\n", anotherString);

    return 0;
}