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

1.Count the number of blanks.
2.Replace the counted number of blanks by a single one.
3.Print the characters one by one.

<code>
main()
{
    int c, count;
    count = 0;
    while ((c = getchar()) != EOF)
    {
        if (c == ' ')
        {
            count++;
            if (count > 1) 
            {
                putchar ('\b');
                putchar (' ');
            }
            else putchar (' ');
        }
        else 
        {
            putchar (c);
            count = 0;
        }
    }
    return;
}
</code>

Answer 2

for(nb = 0; (c = getchar()) != EOF;)
{
    if(c == ' ')
       nb++;
    if( nb == 0 || nb == 1 )
       putchar(c);
    if(c != ' '  &&  nb >1)
       putchar(c);
    if(c != ' ')
       nb = 0;
 }

Answer 3

This is what I got:

while ch = getchar()
   if ch != ' '
      putchar(ch)
   if ch == ' '
      if last_seen_ch != ch
         putchar(ch)
   last_seen_ch = ch

Answer 4

Since relational operators in C produce integer values 1 or 0 (as explained earlier in the book), the logical expression "current character non-blank or previous character non-blank" can be simulated with integer arithmetic resulting in a shorter (if somewhat cryptic) code:

int c, p = EOF;
while ((c = getchar()) != EOF) {
    if ((c != ' ') + (p != ' ') > 0) putchar(c);
    p = c;
}

Variable p is initialized with EOF so that it has a valid non-blank value during the very first comparison.

Answer 5

I wrote this and seems to be working.

 # include <stdio.h>
 int main ()
{

int c,lastc;
lastc=0;
while ((c=getchar()) != EOF)
    if (((c==' ')+ (lastc==' '))<2)
        putchar(c), lastc=c;
 }

Answer 6

First declare two variables character and last_character as integers.when you have not reach the end of the file( while(character=getchar() != EOF ) do this; 1. If character != ' ' then print character last_character = character 2. If character == ' ' if last_character ==' ' last character = character else print character