Reverse string c

reverse.c

#include <stdio.h>

int main()
{
   char s[50], r[50];
   int c = 0;
   int begin;
   int end;

   printf("Digite algo:\n");
   gets(s);

   // Calcula o tamanho da string
   while (s[c] != '\0')
      c++;

   end = c - 1;

   for (begin = 0; begin < c; begin++) {
      r[begin] = s[end];
      end--;
   }

   r[begin] = '\0';
   printf("%s\n", r);
   return 0;
}