Thread: Reverse array of characters

Code:

#include <stdio.h> 
#include <string.h> 
#include <conio.h> 
#include <math.h> 

void reverseAr(char ar[], int n); 

int main() 
{ 
 int choice; 
 char *abc= ar[];

switch (choice) { 
 case 1:
         reverseAr(ar);
     break;

void reverseAr(char ar[], int n) 
{
    char c;
    char *p, *q;
 
    p = ar;
    if (!p)
        return;
 
    q = p + 1;
    if (*q == '\0')
        return;
 
    c = *p;
    reverseAr(ar[]);
 
    while (*q != '\0') {
        *p = *q;
        p++;
        q++;
    }
    *p = c;
 
    return;

}

My codes keep couldn't get the reverse array of characters. Do anyone mind to tell me where is my mistake? Thank you in advance.

This code seems needlessly complicated. As laserlight pointed out there seems to be an odd mix of recursion and iteration. If you want to do it recursively stick to recursion and don't have the unrequired iterative loop (the recursive solution, by the way, will be an example of tail recursion which is easily converted to an iterative solution). I suggest that doing the recursive version first, and then converting this solution to an iterative solution might be valuable for learning.

To help with the recursive solution, answering these questions may help...

* If the string length is 1, how would this be reversed?
* If the string length is 2, how would this be reversed?

Another question:

* If you want to swap the first character in a string with the final character in a string, how would you do this?

I couldn't initialize the array as I have to get the array of characters from user input, hence I do not know how to do so.

Code:

void reverseAr(char ar[], int n) 
{ 	
   int i=0,j;
   char temp;
   
   int len = strlen(ar);
   if (n==0 || n==1)
      return;
   else
   {


temp=*ar;
  *ar=ar[n-1];
  ar[n-1]=temp;
   }
  return reverseAr(ar+1,n-2);
}