François CholletVerified account

Is there a way to assign values to objects such that if you sum some values you can figure out the objects just from the sum? For example, if values are $10, $15, $20, $25, and $30, but you're given just a sum of $40, you don't know whether it's $10 and $30, or $15 and $25.

Context is that some ad networks don't let you view individual conversion details, but just the total. They do let you pass in a conversion value though. So I'm wondering whether we can hack the conversion values to figure out the individual conversions.

If you can use large integers or many decimals, a trivial way to implement it is to use the nth decimal as identifier, e.g. a=0.1, b=0.01 or a=1, b=10 With more complex schemes you can store multiple items per decimal, e.g. 0.2 and 0.3 and 0.4 (assuming max 1 occurrence each)