All ten problems on their headline examples
===========================================

 1. isBalanced("{[()]}") = true; isBalanced("([)]") = false
 2. evaluate([2, 1, +, 3, *]) = 9; 7 / -3 truncates toward zero: -2
 3. push -2, 0, -3: getMin = -3; pop; top = 0, getMin = -2  (both implementations agree)
 4. nextGreater([1, 3, 4, 2]) = [3, 4, -1, -1]
 5. dailyTemperatures([73, 74, 75, 71, 69, 72, 76, 73]) = [1, 1, 4, 2, 1, 1, 0, 0]
 6. nextGreaterCircular([1, 2, 3, 4, 3]) = [2, 3, 4, -1, 4]
 7. largestRectangle([2, 1, 5, 6, 2, 3]) = 10
 8. decode("3[a2[bc]]") = "abcbcabcbcabcbc"; decode("2[abc]3[cd]ef") = "abcabccdcdcdef"
 9. enqueue a, b, c; dequeue = a; enqueue d; dequeue = b; peek = c; size = 2
10. push a, b, c; top = c; pop = c; pop = b; size = 1