A

degenerate case is a instance of a problem whose

parameters differenciate it from all other possible cases. These cases of problems are often

trivial seeming

boundary conditions, and in a

inductive proof or

recursive solution the degenerate case is often the

terminal case.

For example, consider problem number 2 in hard interview questions (with the solution quarter game solution). A strategy must be generalized for the placement of a quarter on a table with an unspecified diameter (presumably non-negative). As mentioned in the solution node, one degenerate case of this problem is where the diameter of the table is equal to the diameter of the quarter. Another degenerate case would be a table with a diameter of zero.

In computer programming, as well as with mathematical proofs, degenerate cases can often pose problems that the general cases do not, and should be tested carefully.