The code gives me correct answer on my computer but it shows wrong when I submit

help
1

The link to the question is here: CodeChef: Practical coding for everyone

I have run all the test cases on my computer(Using XCode on mac) and they give the expected out. But the answer still comes out to be wrong on CodeChef.

2

The question clearly states to print each answer in a new line. you need to replace cout<<sum; with cout<<sum<<"\n";

3

Thanks! That works.

4

@everule1 The same happens to me in this problem as well. CodeChef: Practical coding for everyone

I am already printing numbers on a new line…

5

Okay tell me what is 100! ? do you think it’s lesser than 4\times10^{18} ? Will it fit in any standard datatype?

6

I don’t think so… that is why I used long long int. If something is even bigger than that, how do I handle the numbers?

7

There are 2 ways. Use a digit vector, or use python.

8

I have not yet learned Python. I recently finished C++ and I would like to practice more with it before moving on to other languages. Can you please tell me about a reliable and good resource(website) where I can learn about “digit vector”?

I am familiar with the concept of vectors but digit vector is new to me.

9

read the article about big integer in c++ on geekforgeeks. then implement it yourself.

10

I don’t know where to learn it but it’s not complex at all. we just code how we do multiplication.

int digits1[160]={0};//100! has 157 digits
     int digits2[160]={0};
     digits1[0]=1;
     for(int i=2;i<=n;i++){
         for(int j=0;j<160;j++){
             digits2[j]+=digits1[j]*i;//we multiply the digit
             digits1[j]=0;  //we set it to 0, for the next multiplication
             digits2[j+1]+=digits2[j]/10; //add the carryover to the next digit
             digits2[j]%=10; //remove the carryover from here
         }
         swap(digits2,digits1);
       }
11

Thank you @everule1! That helps :slight_smile: