code teaser

[Helevitia]

A co-worker presented me with some code the other day. I just started learning so I don't know what the answer is. Apparently it was on an aptitude test for a job here at my work.

int i, n = 20;
for (i = 0; i < n; i--)
printf("-");

Rules:

You have to print '-' 20 times by adding or removing or replacing only a single character from the code.

There are 3 possible solutions for the above question. What are they ?

Duration:

10 min.

[Helevitia]

btw, I compiled it just to see what would happen. I also tried changing things but nothing I did would bring it to the desired resolution.

[Jammrock]

What programming language?

Jammrock

[Helevitia]

Originally posted by Jammrock
What programming language?

Jammrock

I used C.

Dave

[Gurm]

I'll think about it for a while, but I see no obvious solutions to this problem, let alone 3.

- Gurm

[Gurm]

Oops. Got one.

Solution 1:

Change the for loop to read:

for (i=0; i < n; n--)

You're decrementing N instead of I.

- Gurm

[ZokesPro]

I'm gonna try...

Original code:

int i, n = 20;
for (i = 0; i < n; i--)
printf("-");

Change:

int i, n = 20;
for (i = 0; i > n; i--)
printf("-");

I know a little about C, I'll laugh if I get it right.

[Gurm]

Solution #2:

Change the for loop to read:

for (i=0; -i < n; i--)

That'll work too.

- Gurm

[Helevitia]

Originally posted by Gurm
Oops. Got one.

Solution 1:

Change the for loop to read:

for (i=0; i < n; n--)

You're decrementing N instead of I.

- Gurm

I just talked to my buddy and this is correct. I also know the second solution. neither of us know the third.

Dave

[Gurm]

Sorry Zokes.

That won't work because i is NEVER greater than n.

[Helevitia]

Originally posted by Gurm
Solution #2:

Change the for loop to read:

for (i=0; -i < n; i--)

That'll work too.

- Gurm

This is correct as well.

[ZokesPro]

Originally posted by Gurm
Sorry Zokes.

That won't work because i is NEVER greater than n.

Oh well. (I'm only on chapter 2 of like 40 on how ot learn C++)

[Rob(QG)]

What about?

for (i=0; i + n; i--)

Worked out #2 too, but gurm beat me to it - grrrr.

[Gurm]

Rob: That's it! I was about to post it but you beat me to it!

i+n evaluates TRUE until i reaches -20 at which point it evaluates FALSE.

Excellent job!

- Gurm

[Rob(QG)]

Tricky little blighter that one