Spreadsheet Problem

[aklepatc]

Design and implement a simplified spreadsheet. Spreadsheet consists of cells. Every cell has a string id. All ids are valid so there is no need to validate them. A cell contains an integer value or a formula like "=A1+B1". You can assume that all formulas are valid and "+" is the only operation that needs to be supported.

What is wrong and what is very wrong with my original solution?
https://go.dev/play/p/v0SXCGdaQsu

JIC: this is not meant to be language-specific. If you at least can read my Go then you are all set.

Comments

[sassa_nf]

No recursion support? No self-reference check?

[aklepatc]

Yes and yes!

A little more high level though... Even without loops (self-references) spreadsheet is some graph (recursion) and the first take solution "flattens" it.

[sassa_nf]

The quoted solution doesn't flatten it. It assumes the referenced cells always contain a value, not another formula. That's what I mean by recursion support.

I don't see other problems - except normally you'd want to initialize the accumulator before the loop; it works here only because it happens we want it to be 0, just what s.val[...] does on missing key, but I'd still call out the absence of a deliberate initialization.

Curious to know what else is wrong with it.

[aklepatc]

I think, you nailed it!