C-Code demonstrates in-place strings reverse.

StringReverse.c

#include "pch.h"
#include <iostream>

// Implement "reverse" to reverse the passed string in-place.
void reverse(char *string) 
{
  int length = strlen(string); // cache string length
  int j = 0;  // first to last increment

  // loop over string elements, last to first
  for (int i = length - 1; i >= 0; i--)
  {
    char last = string[i];  // store last char
    char first = string[j]; // store first char
    string[i] = first;      // add first to last
    string[j] = last;       // add last to first

    // check if we have reached the mid point, if so break
    if (i == j)
    {
      break;
    }
    else
    {
      j++;
    }
  }
}

int main() {
  char astring[] = "Hello, tacocat.";
  reverse(astring);
  printf("%s\n", astring);
  return 0;
}