Question

What would be the easiest way to compare multiple arrays, and remove duplicates?

So (arrays inside arrays in this case)…

a = [[2, 1], [3, 3], [7, 2], [5, 6]]  
b = [[2, 1], [6, 7], [9, 9], [4, 3]]  
c = [[2, 1], [1, 1], [2, 2], [9, 9]]  
d = [[2, 1], [9, 9], [2, 2], [3, 1]]  

…would come out (with priority given to array a, then b, then c, then d)

a = [[2, 1], [3, 3], [7, 2], [5, 6]]  
b = [[6, 7], [9, 9], [4, 3]]  
c = [[1, 1], [2, 2]]  
d = [[3, 1]]  

Answer 1

It’s just set difference or subtraction and you can write it as such. Operator overloading can be a bliss 🙂

a is what it is.

a
[[2, 1], [3, 3], [7, 2], [5, 6]]

b = b - a
[[6, 7], [9, 9], [4, 3]]

c = c - b - a # or c - (a + b)
[[1, 1], [2, 2]]

d = d - c - b - a # or d - (a + b + c)
[[3, 1]]