递归C中的反向数组

Question

Here's a part of my code, where I am trying to reverse a string recursively:

    char reverse[10];
    gets(reverse);
    reverseString(reverse, (strlen(reverse) - 1));
    void reverseString(char ar[], int n)
    {
        if (n == 0)
        {
            return;
        }
        else
        {
            int temp = ar[n];
            ar[n] = *(ar);
            *(ar) = temp;
            reverseString((ar + 1), (n - 1));
        }
    }

When I enter the string "hello" it changes the string to "ohell". I need it to reverse the string totally to "olleh". Can someone help?

Answer 1

Since you swap the first and last element of the array, you should recursively call the function with the remaining n-2 elements (instead of n-1 ),

void reverseString(char ar[], int n)
{
    if (n <= 0)
    {
        return;
    }
    else
    {
        int temp = ar[n];
        ar[n] = *(ar);
        *(ar) = temp;
        reverseString((ar + 1), (n - 2));
    }
}

(I have assumed that reverseString and reverseAr in your code are actually the same functions, perhaps some copy-paste error.)

Answer 2

# include <stdio.h>

/* Function to print reverse of the passed string */
void reverse(char *str)
{
   if(*str)
   {
       reverse(str+1);
       printf("%c", *str);
   }
}

/* Driver program to test above function */
int main()
{
   char a[] = "Geeks for Geeks";
   reverse(a);
   getchar();
   return 0;
}