Min and max stacks

Questions 1 to 5 of 6

1. 1. After the pushes 5, 3, 7, 3, 1, why is the 7 not copied to mins?

   Because 7 was pushed after the first 3Because mins only keeps values that are pushed exactly twiceBecause 7 is larger than the current minimum, 3, so it is not a new minimumBecause odd numbers are never copied
2. 2. Why does push use <= instead of <?

   So that the stack can hold negative numbersSo that pop no longer needs to compare valuesSo that min() returns the value from before the pushSo that every copy of the current minimum gets its own entry in mins, so each pop removes exactly one
3. 3. What does this print, using MinStack from this lesson? ``python s = MinStack() s.push(6) s.push(2) s.push(2) s.pop() s.pop() print(s.min()) ``

   20IndexError6
4. 4. What does this print, using MaxStack from worked example 3 of this lesson? ``python s = MaxStack() s.push(2) s.push(7) s.push(7) s.push(3) s.pop() s.pop() print(s.max()) ``

   3725
5. 5. Which statements about the MinStack in this lesson are true? Pick all that apply.

   Pick every answer that is true.

   min() scans every value in the list to find the smallest onepush copies x to mins when x is less than or equal to the current minimumpop removes the last item of mins every time it runsmin() reads the last item of mins, so it takes one step