K&R Exercise 1-9 (C)

Question

\"Write a program to copy its input to its output, replacing each string of one or more blanks by a single blank.\"

I\'m assuming by thi

Answer 1

Solution1: as per topics covered in the k&R book:

#include 

int main()
{
    int c;

while ((c = getchar()) != EOF)
    {
       if  (c == ' ') 
       {while ( getchar() == ' ' )
        ;  // ... we take no action
        }

        putchar(c);

    }

return 0;
}

Solution2 : using program states:

int main()
{
    int c, nblanks = 0 ;

while ((c = getchar()) != EOF)  
{
   if (c != ' ')
       { putchar(c);
         nblanks = 0;}

   else if (c==' ' && nblanks == 0) // change of state
            {putchar(c);
             nblanks++;}
}
return 0;
}

Solution3 : based on last seen char

int main()
{
int c, lastc = 0;

while ((c = getchar()) != EOF)
    {
        if ( c != ' ')
        {putchar(c);}


        if (c == ' ')
        {
            if (c==lastc)
                ;
            else putchar(c);

        }

        lastc = c;
    }

return 0;
}