Combinatorial problems are hard. The number of ways to arrange N guests in N seats at a seated event (such as a wedding or gala) is N!. Even with only 60 guests

Combinatorial problems are hard. The number of ways to arrange N guests in N seats at a seated event (such as a wedding or gala) is N!. Even with only 60 guests, there are already more possible seating permutations that there are believed to be atoms in the observable universe. The solution space for hundreds of guests is mind boggling large. I sometimes try to explain this to customers of my seating planning software (PerfectTablePlan) when they complain that the auto seating algorithm has separated 2 people in a 500 seat event, but I don't think many of them understand!