Nice!

print your inputs? see Docs if you don't know how.

Duplicate issue. Fixed. Closing.

Fixed.

It's a 4 kyu, solvers can trace inputs themselves.

duplicate of this issue

duplicate of this issue

Solved the problem. The question arose due to a misunderstanding. Clear question == clear answer.

You haven't implemented this case:

• If two monomials have the same number of variables, they appears in lexicographic order, e.g.:
  "a+ca-ab" -> "a-ab+ac", "xzy+zby" ->"byz+xyz"

In the first example, 4a should come first before b since a < b in lexicographical order. Same with the second example, fk < kq.

Hi! An error is issued:
poly = 3a+b+4ac+bc-ab+3a-cb-a-a
Sorry :( : 'b+4a-ab+4ac' should equal '4a+b-ab+4ac'
by the condition of the problem, this is true! 'b+4a-ab+4ac'

poly = -8fk+5kv-4yk+7kf-qk+yqv-3vqy+4ky+4kf+yvqkf
Sorry :( : '-kq+3fk+5kv-2qvy+fkqvy' should equal '3fk-kq+5kv-2qvy+fkqvy'
by the condition of the problem, this is true! '-kq+3fk+5kv-2qvy+fkqvy'

Fix it or test it or tell me where I'm wrong.

Enabled in this fork