Discussion @ 1023. Buttons @ Timus Online Judge

Can someone give me a test case where my program fails?

Posted by Junjie Liang 11 Feb 2002 20:45

#include <stdio.h>

long min, num, i;

int main() {
scanf("%ld", &num);
min = num - 1;
if (num % 2 == 0) min = (num / 2) - 1;

for (i = 3; i*i <= num; i++)
    if (num % i == 0)
      if ((i-1) < min) {
        min = i-1;
        break;
      }

printf("%ld\n", min);

return 0;
}

Re: Can someone give me a test case where my program fails?

Posted by Ivan Georgiev 11 Feb 2002 21:25

There is a restriction -- the answer is >= 2;
so for example the answer for 4 is 3 (not 1);

Good luck.

Re: Can someone give me a test case where my program fails?

Posted by Junjie Liang 13 Feb 2002 08:13

Thanks, but I still get WA. Is this revised copy wrong as well?

#include <stdio.h>

long min, num, i;

int main() {
scanf("%ld", &num);
min = num - 1;
if (num == 4) {
    min = 3;
}

if (num % 2 == 0) min = (num / 2) - 1;

for (i = 3; i*i <= num; i++)
    if (num % i == 0)
      if ((i-1) < min) {
        min = i-1;
        break;
      }

printf("%ld\n", min);

return 0;
}

Re:

Posted by Ivan Georgiev 13 Feb 2002 22:15

Yes it is.
You give answer 1 to input 4 again.

Silly me! Anyone I have AC now...THANKS! (-)

Posted by Junjie Liang 14 Feb 2002 14:54

Discussion of Problem 1023. Buttons