c program for the reverse the digits

Question

I am looking for the C program for reverse the digits like below:

If i enter:

123456

Then the result would

Answer 1

Here is a simple solution to this complex problem:

#include 

int main()
{
    int ch;
    ch = getchar();
    if (ch != '\n') {
        main();
        printf("%c", ch);
    }
}

---

A new version that outputs the newline:

#include 
#include 

static void newline(void)
{
    printf("\n");
}

int main()
{
    int ch;
    ch = getchar();
    if (ch != '\n') {
        main();
        printf("%c", ch);
    } else {
        atexit(newline);
    }
}