Notes

  • Iteration: a repeating portion of an algorithm, repeats a specified number of times or until a given condition is met
  • Iteration Statements: change the sequential flow of control by repeating a set of statements zero or more times, until a stopping condition is met
  • Repeat Until: if the condition evaluates to true initially, the loop body is not executed at all, due to the condition being checked before the loop
  • Range function: use variable to represent what the range of numbers the output can show. Use with for loop
    • when using the range function, the last number, or the ending value, is not included in the output, therefore we would have to add 1 to receive the correct output
  • For loop: process stops if next element meets statement
  • While loop: process is repeated until statement is met
  • In lists:
    • append(): adding element to the end of the list
    • insert(): adding an element in a specific position
    • remove(): remove an item from a list
    • len(): returns number of items in a list
    • sort(): permanently changes order of list
    • sorted(): returns copy of list, leaving original copy unchanged
    • range(): range of number able to use, makes working with numbers more efficient
    • min(): find the least value in a list
    • max(): find highest value in a list
    • sum(): sum of all values in a list
  • Traversing a list is process of visiting each element in a list in a sequential order. Used to access, search for, and modify elements in the list
    • Complete Traversal: All elements in a list are assessed
    • Partial Traversal: Only a given portion of elements are assessed
    • Iterative Traversal: When loops are used to iterate through a list and to access each single element at a time.

Hacks

Section 3.8.1

Iteration: part of an algorithm that is repeated until a certain condition is met

  1. Start
  2. The number of pretzels in the pack is 6
  3. Eat one fruit snack, number of pretzels in pack goes down by 1
  4. How many pretzels are left?
  5. Repeat step 3 until number of pretzels is 0
  6. Display that pack is empty
  7. Finish
pretzel = 6
while (pretzel > 0):
    pretzel -= 1
    print(pretzel)
    if pretzel == 0:
        print("All done!")

5
4
3
2
1
0
All done!

Section 3.8.2

Iteration Statement: statements to be executed zero or more times, unless a stopping condition is met

nums = [5, 4, 3, 2, 1]
for i in nums:
    if i <= 2:
        break
    print(i)

5
4
3

number = 3
while number <= 81:
    print(number)
    number += 13
number = 0 

3
16
29
42
55
68
81

3.10 

nums = [38, 45, 67, 83, 78]

min = 40

for num in nums:
    if num < min:
        min = num

print(min)

38

APCSP Reference Page Notes

  • PROCEDURE procName(parameter1,
    parameter2, ...)
    {
    <# block of statements>
    }
    • procName: a procedure that takes zero or more arguments
    • procedure procName can be called using "procName(arg1, arg2, ...)", where arg1 is assigned to parameter1, arg2 is assigned to parameter2, etc.

  • PROCEDURE procName(parameter1,
    parameter2, ...)
    {
    <# block of statements>
    RETURN(expression)
    }
    • return statement may appear at any point inside the procedure and causes an immediate return from the procedure back to the calling statement.
    • value returned by the procedure procName can be assigned to the variable result using "result ← procName(arg1, arg2, ...)"

  • APPEND(aList, value)
    • length of aList is increased by 1, and value is placed at the end of aList

  • REPEAT UNTIL(condition)
    {
    <# block of statements>
    }
    • code is repeated until the Boolean condition evaluates to true

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