<style> :not(ul) + ol { counter-reset: list-ctr; list-style-type: none; list-style-position: outside; } :not(ul) + ol > li { counter-increment: list-ctr; } :not(ul) + ol > li::before { content:"Q" counter(list-ctr) ". "; margin-left: -25px; } ol ul { list-style-type: lower-roman; } ol ol { list-style-type: lower-alpha; } ol ul ul { list-style-type: lower-roman; } ul ol { list-style-type: circle; } ul { list-style-type: decimal; } ul ul { list-style-type: lower-alpha; } ul ul ul { list-style-type: lower-roman; }

Chapter 36

1. > FUNCTION peek -> STRING AS
        IF isEmpty DO
            OUTPUT Stack is empty
        ELSE DO
            RETURN s[top]
        END IF
    END FUNCTION
   

2. Stack operation	Stack contents	Return value

   • | ['Blue', 'Red'] | - Pop | ['Blue'] | 'Red' Pop | [] | 'Blue' Push 'Yellow' | ['Yellow'] | None

Exercises

• ​

  • Stack

  • Overflow, where the code attempts to add an item to an already-full stack, such that it overwrites other bits of memory (or itself)

  • Stacks can be used for holding return addresses during execution, which are popped off during return

  • >  PROCEDURE reverse_queue <- Queue queue AS
          SET stack TO CREATE Stack
          WHILE ! (CALL queue.isEmpty) DO
              CALL stack.push WITH CALL queue.pop
          END WHILE
          WHILE ! (CALL stack.isEmpty) DO
              CALL queue.push WITH CALL stack.pop
          END WHILE
      END PROCEDURE