rot13#

rot13.c

/* rot13 algorithm. Very Simple and Interesting */

#include<stdio.h>
#define ROT 13

int main(void)
{
    int c,e;

    while((c=getchar())!=EOF)
    {
        if(c >='A' && c <='Z')
        {
            if((e = c + ROT) <= 'Z')
                putchar(e);
            else
            {
                   e = c - ROT;
                putchar(e);
            }
        }
        else if(c >='a' && c <='z')
        {
            if((e= c + ROT) <= 'z')
                putchar(e);
            else
            {
                e = c - ROT;
                putchar(e);
            }
        }
        else
            putchar(c);
    }

return 0;
}