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Comment by drdo | Hacker News Reader

Wasn't hard. The problems could be better explained, for example in the second one they should clarify that the binary tree is balanced and that each node is one character.

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> binary tree is balanced and that each node is one character

I found that pretty intuitive given they tell us it is a tree with 2^n-1 nodes, and that this is then umber of characters in the text file.

What I'm wondering about is what the '=' pad character means in the context of non-valid base64 (i.e. isn't it the same as the 'A' character - a null?)

you're right - we should explain that it's balanced.

Any comment in regard to my question above? At present, question 2 has serious ambiguity as to how one should interpret the data. Clearly each character represents one node, but again, there is no clear procedure for converting values. Padding makes no sense in this context.

Can you clarify?

It's just as ASCII, you should sum the leaves that have ASCII digits (sum their digit value, not their ASCII code) and ignore the non-digit leaves.

I still don't follow. Digit value rather than ASCII code... you mean Base64 digit value? If so, do you just ignore the pad char? (I mean... by "non-digit leaves" you are referring to the leaves represented by '=' and only those?)

EDIT: I understand now... jeez that was a run-around! Ascii encoded decimal! Thanks for the clarifying replies all over.

I think it's literally one ASCII code (byte) per each of the 1023 nodes in the tree. Any time there's a non-digit in one of the leaf positions you ignore it.

There's no Base64, it's just regular ASCII, for each leaf that has an ASCII character '0' through '9', you sum 0 through 9 respectively.

Ah, that's the part I was missing. When I didn't see a digit in the first leaf I thought I had it wrong.

The characters should be interpreted as ASCII.

One quickly realises that you must mean a balanced tree, since otherwise there would be no unique solution, but it would still be nice if it was explicit in the text.

yeah I thought it was base64 and that was annoying

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