Optimal_Aces's blog

What is the approach for this problem ?
By Optimal_Aces, history, 5 years ago, In English

https://www.codechef.com/problems/CKISSHUG

My method :- if first place is H then there are 2^(n-1) possibilities if first place is K then there are 2^(n-1/2) possibilities but this method is not right .

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5 years ago, # |
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I fully solved it on Codechef.

The formula is { 2^(((n-1)/2)+2) -2 } + 2^(n/2) if n is even.

You have to calculate power of 2 using Modular Exponentiation. You can read it about here https://www.geeksforgeeks.org/modular-exponentiation-power-in-modular-arithmetic/

This is my code https://www.codechef.com/viewsolution/26865644 Hope it helps :) Please upvote it if it helps.

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