stack before: [3, -5, 1, 2, -4]
stack after:  [-4, -5, 2, 1, 3]
queue before: [1, 8, 7, 2, 9, 18, 12, 0]
queue after:  [1, 0, 7, 18, 9, 2, 12, 8]
queue before: [1, 8, 7, 2, 9, 18, 12]
queue after:  [1, 18, 7, 2, 9, 8, 12]