Secret santa algorithm

Question

Every Christmas we draw names for gift exchanges in my family. This usually involves mulitple redraws until no one has pulled their spouse. So this year I coded up my own

Answer 1

Hmmm. I took a course in graph theory, but simpler is to just randomly permute your list, pair each consecutive group, then swap any element that is disallowed with another. Since there's no disallowed person in any given pair, the swap will always succeed if you don't allow swaps with the group selected. Your algorithm is too complex.