Hi,

I was trying to solve SEALCM of JAN long challenge-15.

problem link: problem link

this question can be solved by inclusion exclusion principle.

I have seen code of rajat1603

solution link: soln link

But I am unable to understand working of f[i][j] (line 84-100) and also some part of s1,s2,s3,s4,s5 and final.

It would be nice if someone can mention working of f[i][j] or provide his own way to solve this question by

inclusion-exclusion principle.

For newbies like us It would be great if such explanations will be givenâ€¦

Read this : [explaination of SEALCM - general - CodeChef Discuss][1]

Well rather than looking at the code you should focus on understanding the concept first.

As i have said we have to calculate y = n(NOT(A) U NOT(B) U NOT(C) U NOT(D))

Take a = not(A), b = not(B), c = not(C), d = not(D).

y = n(a U b U c U d).

Now first expand it using **Inclusion-Exclusion Principle**. Then , if you really understand Set Theory , you will be able to see that to calculate the answer you will also require **deMorganâ€™s Law**.

First do it on paper and then move to coding it i.e before coding fully expand y and write it somewhere then you would be able to grasp the real solution.

And first study the concepts mentioned in **Bold characters**.

[1]: explaination of SEALCM - general - CodeChef Discuss

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Hi @thechamp103,

You are the real champ!! I got it!

Still I want to confirm this::

Y = power(m-m/p,n)+power(m-m/q,n)+power(m-m/r,n)+power(m-m/s,n)-

```
power(m-m/p-m/q+m/(p*q),n)- power(m-m/p-m/r+m/(p*r),n)-power(m-m/r-m/q+m/(r*q),n)-
power(m-m/p-m/s+m/(p*s),n)-power(m-m/s-m/r+m/(s*r),n)-power(m-m/s-m/q+m/(s*q),n)+
power(m- m/p -m/q -m/r +m/(p*q)+ m/(q*r)+m/(p*r) - m/(p*q*r),n)+
power(m-m/p-m/q-m/s+m/(p*q)+m/(p*s)+m/(q*s)-m/(p*q*s),n)+
power(m-m/s-m/q-m/r+m/(s*q)+m/(s*r)+m/(q*r)-m/(s*q*r),n)+
power(m-m/p-m/r-m/s+m/(p*r)+m/(p*s)+m/(r*s)-m/(p*r*s),n)-
power(m-m/p-m/q-m/r-m/s+m/(p*q)+m/(q*r)+m/(p*r)+m/(r*s)+m/(p*s)+m/(q*s)
- m/(p*q*r)-m/(q*r*s) - m/(p*q*s) - m/(p*r*s) + m/(p*q*r*s),n)
```

where p,q,r,s are A,B,C,D.

Is this your Y??

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I donâ€™t know the solution, but your handle is amazing

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My khopri is also amazing

Believe me,I am acquainted to you

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Hi @thechamp103,

I am not able to understand your uni function as well as lines 77-88.

I know inclusion exclusion principle and set generation but still I am not able tto get those part

Clearly,I have not implemented inclusion exclusion principle yet.

Could you please guide me??

Yup that looks about right.