How do I use putchar to "squeeze" characters (Ansi-C)

Question

i was wondering if i could get some help for my code. I put some partial code below

/*reads char by char til EOF*/
while((c = getchar()) != EOF)
{

    if(c == '\t')
    {
        putchar(' ');
    }
    else if(c == ' ')
    {
        putchar('d');
    }
    else
    {
        putchar(c);
    }
}

What I am trying to do right now is squeeze space characters entered by the user. So if the user puts in:

a[SPACE][SPACE][SPACE][SPACE][SPACE][SPACE][SPACE][SPACE]a

The output should be just

a[SPACE]a

Right now i have it set up that it replaces all spaces for d's for testing purposes. How would I change my code so that it just prints out 1 space instead of all the spaces the user puts in.

Thanks for any help in advance.

Answer 1

Just keep a whitespace flag:

int lastWasSpace = 0;
while((c = getchar()) != EOF) {
    if(c == '\t' || c == ' ') { // you could also use isspace()
        if(!lastWasSpace) {
            lastWasSpace = 1;
            putchar(c);
        }
    } else {
        lastWasSpace = 0;
    }
}

Answer 2

One solution:

/*reads char by char til EOF*/
int hasspace = 0;

while((c = getchar()) != EOF)
{
    if (isspace(c))
        hasspace = 1;
    }
    else
    {
        if (hasspace)
        {
            hasspace = 0;
            putchar(' ');
        }
        putchar(c);
    }     
}