Here are the programming problems I found very enjoyable to solve:

N queen problem

The wolf has started his way

Find all placements of N queens on the NxN sized chessboard so that no two queens threaten each other.

Find solution for as big N as you can.

7

The wolf is patiently walking

You are given the false expression:

1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 = 7

You can use any number of parentheses to make this expression true.

Find all solutions containing no useless parentheses.

Tic-tac-toe

The wolf is walking little faster

You are given some state of the Tic-tac-toe game. You have to answer the question: who will win if both players play ideally?

35

You are given the expression:

The wolf is gaining speed

((((1?2)?3)?4)?5)?6 = 35

You can replace any ? with the one of the next operations +, -, *, /.

Find all configurations where the expression is true.