Input unknown number of integers in a line...

[none]

If I need to add up all integers in a line (they're separated by space)
How can I do that??

e.g.
input : 1 4 5 2 3
sum : 15
input : 2 3
sum: 5

[Ben Pfaff]

none <""root\"@(none )"> writes:

If I need to add up all integers in a line (they're separated by space)
How can I do that??

You could write a C program to do it. Have you tried?
--
char a[]="\n .CJacehknorstu" ;int putchar(int);in t main(void){unsi gned long b[]
={0x67dffdff,0x 9aa9aa6a,0xa77f fda9,0x7da6aa6a ,0xa67f6aaa,0xa a9aa9f6,0x1f6}, *p=
b,x,i=24;for(;p +=!*p;*p/=4)switch(x=*p& 3)case 0:{return 0;for(p--;i--;i--)case
2:{i++;if(1)bre ak;else default:continu e;if(0)case 1:putchar(a[i&15]);break;}}}

[none]

I searched for functions..
but still can't find any clues..

My first thought is scanf the whole line,
and use itoa function to add the integers one by one,
but how can I isolate the substring and use itoa function to turn it
into integer??

just like,
10 23 234
I can detect the 2 spaces,
so I need to cut the 2 characters and place it to another character array??

Ben Pfaff mentioned:

none <""root\"@(none )"> writes:

If I need to add up all integers in a line (they're separated by space)
How can I do that??

You could write a C program to do it. Have you tried?

[Ben Pfaff]

none <""root\"@(none )"> writes:

My first thought is scanf the whole line,
and use itoa function to add the integers one by one,
but how can I isolate the substring and use itoa function to turn it
into integer??

I think you are trying to work too hard. There is no reason to
read the entire line all at once. Read and accumulate one number
at a time.
--
int main(void){char p[]="ABCDEFGHIJKLM NOPQRSTUVWXYZab cdefghijklmnopq rstuvwxyz.\
\n",*q="kl BIcNBFr.NKEzjwC IxNJC";int i=sizeof p/2;char *strchr();int putchar(\
);while(*q){i+= strchr(p,*q++)-p;if(i>=(int)si zeof p)i-=sizeof p-1;putchar(p[i]\
);}return 0;}

[none]

Thx~

Ben Pfaff mentioned:

none <""root\"@(none )"> writes:

My first thought is scanf the whole line,
and use itoa function to add the integers one by one,
but how can I isolate the substring and use itoa function to turn it
into integer??

I think you are trying to work too hard. There is no reason to
read the entire line all at once. Read and accumulate one number
at a time.

[Lawrence Kirby]

On Thu, 27 Jan 2005 21:30:44 -0800, Ben Pfaff wrote:

none <""root\"@(none )"> writes:

My first thought is scanf the whole line,
and use itoa function to add the integers one by one,
I assume you mean atoi(), C has no itoa() function.
but how can I isolate the substring and use itoa function to turn it
into integer??

I think you are trying to work too hard. There is no reason to
read the entire line all at once. Read and accumulate one number
at a time.

Reading in the whole line using fgets() is a good approach. You could read
in a number at a time using scanf() but then it is more difficult to work
out when you have reached the end of the line, and make sure you haven't
left any training characters in the stream. After reading with fgets() you
could use strtok() to get the test for each number and convert using
atoi() or strtol().

Lawrence

[CBFalconer]

Lawrence Kirby wrote:

On Thu, 27 Jan 2005 21:30:44 -0800, Ben Pfaff wrote:

none <""root\"@(none )"> writes:

My first thought is scanf the whole line,
and use itoa function to add the integers one by one,
I assume you mean atoi(), C has no itoa() function.
but how can I isolate the substring and use itoa function to turn it
into integer??

I think you are trying to work too hard. There is no reason to
read the entire line all at once. Read and accumulate one number
at a time.

Reading in the whole line using fgets() is a good approach. You could read
in a number at a time using scanf() but then it is more difficult to work
out when you have reached the end of the line, and make sure you haven't
left any training characters in the stream. After reading with fgets() you
could use strtok() to get the test for each number and convert using
atoi() or strtol().

Better yet use ggets() and forget about buffer sizes etc. The
result is always a writable string. See:

<http://cbfalconer.home .att.net/download/ggets.zip>

--
"If you want to post a followup via groups.google.c om, don't use
the broken "Reply" link at the bottom of the article. Click on
"show options" at the top of the article, then click on the
"Reply" at the bottom of the article headers." - Keith Thompson

[Ben Pfaff]

Ben Pfaff <bl*@cs.stanfor d.edu> writes:

I think you are trying to work too hard. There is no reason to
read the entire line all at once. Read and accumulate one number
at a time.

In fact, it's easy enough with only one *digit* at a time:

#include <stdio.h>
#include <ctype.h>

/* Read integers from stdin, print their sum to stdout. */
int
main (void)
{
unsigned total = 0, current = 0;

for (;;) {
int c = getchar ();
if (c == EOF)
break;
else if (isdigit (c))
current = current * 10 + (c - '0');
else {
total += current;
current = 0;
}
}
printf ("%u\n", total + current);
return 0;
}
--
"Welcome to the wonderful world of undefined behavior, where the demons
are nasal and the DeathStation users are nervous." --Daniel Fox

[CBFalconer]

Ben Pfaff wrote:

Ben Pfaff <bl*@cs.stanfor d.edu> writes:

I think you are trying to work too hard. There is no reason to
read the entire line all at once. Read and accumulate one number
at a time.

In fact, it's easy enough with only one *digit* at a time:

#include <stdio.h>
#include <ctype.h>

/* Read integers from stdin, print their sum to stdout. */
int
main (void)
{
unsigned total = 0, current = 0;

for (;;) {
int c = getchar ();
if (c == EOF)
break;
else if (isdigit (c))
current = current * 10 + (c - '0');
else {
total += current;
current = 0;
}
}
printf ("%u\n", total + current);
return 0;
}

This brings up a point to me. Obviously the first control
structure that came to your mind was a for loop. To me, I would
start with a while loop, as below.

while (EOF != (c = getchar())) {
}

and only then would I expand the loop, and your code looks just
fine for the purpose, into:

while (EOF != (c = getchar())) {
if (isdigit (c)) current = current * 10 + (c - '0');
else {
total += current;
current = 0;
}
}
printf ("%u\n", total + current);
return 0;

Obviously neither is wrong, but why is there such a basic
difference in the selection of code structure?

--
"If you want to post a followup via groups.google.c om, don't use
the broken "Reply" link at the bottom of the article. Click on
"show options" at the top of the article, then click on the
"Reply" at the bottom of the article headers." - Keith Thompson

[Ben Pfaff]

CBFalconer <cb********@yah oo.com> writes:

Obviously the first control structure that came to your mind
was a for loop. To me, I would start with a while loop, as
below.

while (EOF != (c = getchar())) {
}

and only then would I expand the loop...

As a stylistic issue, I just don't like to combine assignments
and tests. I can understand it just fine, of course, but I
usually avoid doing it in my own code. That's the only reason I
use `for' instead of `while' in that code.
--
"If I've told you once, I've told you LLONG_MAX times not to
exaggerate."
--Jack Klein