Trie interview problem

#1

What would be the approach for the TRIE INTERVIEW problem using TRIES except for the brute force

#2

Hi @ChiragJindal7 ,the approach to this problem would be to construct two arrays lbest and rbest for the left hand side of the expression and for the right hand side of the expression. To calculate lbest[i] we will iterate m from i to i such that (arr[m] ^ arr[m+1] ^ arr[m+2] … arr[i]) is maximised. Then lbest[i] = Max(lbest[i-1], val). Similar can be done for rbest. Now we will calculate val. Let C[i] = (arr[1] ^ arr[2] ^ arr[3] … arr[i]). For some j <= i, C[j-1] ^ C[i] = ( arr[j] ^ arr[j+1] ^ arr[j+2] … arr[i] ). ​We can now say that lbest[i] = max(lbest[i−1],val) where val = maximum of (C[j−1]^C[i]) for j = 1 to i. Now using Tries we can easily calculate ‘val’ in (log arr(max)). We can store the bits of each number in the nodes of trie and iterate through the trie such that we can get the maximum xor possible.

also, you can refer previous discussion for this problem at
http://discuss.codingblocks.com/tags/💡-trie-interview

In case of any doubt feel free to ask :slight_smile:
If you got your answer mark your doubt as resolved

#3

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