Reverse an array of characters using recursion

Problem statement

Write a c program to reverse an array of characters without using recursion

#include<stdio.h>
void reverse(char a[],int i);
int size(char arr[]);
int main()
{
  char arr[55];
  int i;
  printf("enter the array ");
  scanf("%s",arr);
  i=size(arr); 
  reverse(arr,i);
  printf("%s \n",arr);
  return 0;
}
void reverse(char a[],int i)
{
 
  char temp;
  int j;
  for(j=0;j<i/2;j++)
    {
      temp=a[i-j-1];
      a[i-j-1]=a[j];
      a[j]=temp;
    }
  return ;
}
int size(char arr[])
{
  int i=0;
  while(*arr!='\0')
    {
      arr=arr+1;
      i++;
    }
  return i;
}