OJ Board

thanks
i know where is wrong with my code.
and i got ac thanks.

This code is AC:
[c]
#include<stdio.h>
long double n,k,sum,c;
void main(){
while(1){
scanf("%Lf %Lf",&n,&k);
if(n==0) break;
if(k>n/2) k=n-k;
if(k<2){
if(k==0) printf("1\n");
else printf("%.0Lf\n",n);
}
else{
if(n<2) printf("1\n");
else{
if(n<37){
if(n==35) printf("%.0Lf\n",n);
else{
for(sum=1,c=k;c>0;c--,n--) sum*=n;
for(;k>1;k--) sum/=k;
printf("%.0Lf\n",sum);
}
}
else{
for(sum=1,c=k;c>0;c--,n--) sum*=n;
for(;k>1;k--) sum/=k;
printf("%.0Lf\n",sum);
}
}
}
}
}
[/c]

Check the bold part, this line mean if the n is 35 then the output will always be 35.

that only means that judge has not such case ... and this is not a bug ...

Best regards
DM

Well, if the judge doesn't have such case, that's a bug alright!

Judge data does not contain all possible input. So it is not a bug.

i used a very simple algorithm for counting nCr. i used array for solving the problem . cant find any problem , but getting wa all the time . pliiiizzzzzzzzzzzzzzz help . here is my code:---------->

plizzzzzzzzzzzzzzzzzz help me
Bye
Riyad

I think in your program the output may not fit into long int. You may try with long long int or double. Hope this helps

Riyad delete your source code. So that no one can get accepted by changing it.

Hi there!. This is my code:
While running at home I get a right output, but the judge always answers: Runtime Error (SIGSEGV). Does anyone know what happend?.

hey man what u tried is purely brute force . when u r counting the factorial it is going beyond the boundary of long double . as a matter u have to find a tricky way to find the NcR.
regards
RIYAD

why ? ... ^^"

Please help me... T____T

[cpp]
#include <iostream>
using namespace std;
int combi(int n,int m) {
long i,p;
for (i=1,p=1;i<=m;i++)
p = p*(n-i+1)/i;
return p;
}
int main() {
long n,m;
while (cin>>n>>m) {
if (m==0&&n==0) break;
if (m==0) cout << 1 << endl;
else cout << combi(n,m) << endl;
}
return 0;
}
[/cpp]

Hi Frostina,

Remember nCr = n! / ( (r!) * (n-r)!);

So you can either run a loop from r+1 to n or
from n-r+1 to n;

Starting from max( r+1, n-r+1) is certainly better.

I changed this part of your code and got it AC in 0.00 seconds.

And in your combi() function why are you using int n, and int m; when they are long. By the way I think you should use long long.

Hope it helps.

Hi,

I'm still new, so the question might be silly- but it's
frustrating anyway.

Recently I switched from Pascal to C, no special reason,
just for fun.

And now I have a problem with a couple of programs.
They all give a wrong answer in 0.000 seconds.

Quote:
"Your program has not solved the problem. It ran during 0.000 seconds."

The main function's always similar, like the one following (Problem 530):

[c]int main(void)
{
long k, n;
unsigned long p;
while (scanf("%ld %ld",&k,&n) == 2)
if ((k > 0) && (n > 0)){
if (k >= n)
p = binom(k,n);
else
p = binom(n,k);
printf("\n%ld",p);
}
return 0;
}[/c]

The programs run ok on my computer!

Do I have a problem with my program, with the e-mail program
or with the OJ?.

Answers are very appreciated!
Thanks in advance.

WR wrote:And now I have a problem with a couple of programs.
They all give a wrong answer in 0.000 seconds.

It looks like incorrect input handling or incorrect checking for data termination...

The main function's always similar, like the one following (Problem 530):

WR wrote:[c]int main(void)
{
long k, n;
unsigned long p;
while (scanf("%ld %ld",&k,&n) == 2)
if ((k > 0) && (n > 0)){
[/c]

Two observations:

• -here you discard inputs in the form "n 0" while the problem specification allows for k=0;
  -input is terminated by "0 0", you should check for this and exit, although this shouldn't affect your early termination problem.

WR wrote:[c] if (k >= n)[/c]

This check is redundant since prob specification says explicitly that 0<=k<=n.

WR wrote:[c] p = binom(k,n);
else
p = binom(n,k);
printf("\n%ld",p);
[/c]

here you put a newline at the very beginning of the output and the last line of output isn't terminated.

WR wrote:[c]
}
return 0;
}[/c]

The programs run ok on my computer!

You don't have judge input data, do you?

WR wrote: Do I have a problem with my program, with the e-mail program
or with the OJ?.

In this case it looks like it's your program at fault... as most of the times the problem lies in my programs

Ciao!!!

Claudio