Advance Reverse string

Hi there all, Sorry if i post another reverse string. Really need all your help.

I am trying to reverse a string "HELLO" but i need the end result to be like this " OLLEHHELLO" a mirror effect. I cannot use string.h.

Only can use recursion.

I tried modifying some codes on reversing but all failed. Please help

Reverse the string, then concatenate the normal string with the reversed string using strcpy() and strcat().

I cannot use the strcpy function or strrev function

The reverse function is easily done using a for loop and a swap-value function (which you write).

You can also do the concatenate function yourself using a for loop (or two).

I have no idea how you could do it easily with recursion, since you cannot return a string (are not allowed to use string objects).

Code:

---

void Swap(char* C1, char* C2)
{
  char Temp = *C1;
  *C1 = *C2;
  *C2 = Temp;
}

void Reverse(char* String)
{
  int Length = strlen(String);
  for(int i=0; i<(Length/2); i++)
  {
      Swap(&String[i], &String[Length - i - 1]);
  }
}

void Concatenate(char* Buffer, char* S1, char* S2)
{
  int i;
  int L1 = strlen(S1);
  int L2 = strlen(S2);

  for(i=0; i<L1; i++)
  {
      Buffer[i] = S1[i];
  }
  for(i=0; i<L2; i++)
  {
      Buffer[L1 + i] = S2[i];
  }
  Buffer[L1 + L2] = '\0';
}

int main()
{
  char Buffer[256];
  char StrHello[16] = "Hello";
  char StrHelloReverse[16] = "Hello";

  Reverse(StrHelloReverse);
  Concatenate(Buffer, StrHello, StrHelloReverse);
  cout << Buffer;

  return 0;
}

---

Quote:

---

Originally posted by Salem
Mmm, Magos with the C++

---

Hmmm... I rarely check if I'm posting in the C or C++ forum, and since I like cout better than printf I usually use it... :).

#include <stdio.h>

#define MAX_BUFFER_SIZE 256

char buf[MAX_BUFFER_SIZE] = {0};
int i = 0;

char* reverse(char *s)
{
char *p;

for (p = s; *p != '\0'; p++)
;

for (p--; p != s; p--)
buf[i++] = *p;

buf[i++] = *p;

return (char *)&buf[0];
}

main()
{
char *s = "HELLO";

reverse(reverse(s));

printf("%s\n", buf);
}

Quote:

---

Originally posted by Waiting_11

char buf[MAX_BUFFER_SIZE] = {0};

return (char *)&buf[0];

---

1) Why are you returning a global?
2) What's with the horrible cludge of a return statement?

This is so much nicer:

return buf;

Quzah.