CSP - ALGORITHMS

SRSC

BIG IDEA: A FINITE SET OF INSTRUCTIONS THAT ACCOMPLISH A SPECIFIC TASK

SEQUENCING

DO STEPS OF CODE IN THE ORDER SPECIFIED

first step -> second step -> third step

number = int(input("Enter a number: "))

result = number * 2
print("double of " + str(number) + " is " + str(result))

double of 1is 2

Create a variable based on user input
Multiply variable by two
Print out both variables at the end

SELECTION

Choose TWO OR MORE OUTCOMES based on a DECISION or CONDITION

number = 6
if number % 2 == 0:
    print("Even")
else:
    print("Odd")

Even

Set number to 5
If number is divisible by 2 with no remainder, print “Even”
Otherwise, print “Odd”

ITERATION

REPEAT STEPS BASED ON A DECISION or STOP when a condition is met

first step -> second step -> if step 2: true -> first step if step 2: false -> third step -> fourth step

fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
    print(fruit)

apple
banana
cherry

Create a list called fruits
For each fruit in the list, print the fruit

ACTIVITY 1: Robot Pseudocode

Link to Robot Question 2

Write the pseudocode to move the robot onto the gray square.

Available Code:
Move forward
Turn Left
Turn Right

PseudoCode here:

# Math Operations:

print("Addition") #addition
result = 5 + 3
print(result)  # 8

print("\nSubtraction") #subtraction
result = 10 - 4
print(result)  # 6

print("\nMultiplication") #multiplication
result = 6 * 7
print(result)  # 42

print("\nFloat Division") #float division (float = numbers with decimal values)
result = 20 / 4
print(result)  # 5.0

print("\nInteger Division (floor division)") #floor division
result = 20 // 4
print(result)  # 5

print("\nModulus (remainder)") #remainder
result = 10 % 3
print(result)  # 1

Addition
8

Subtraction
6

Multiplication
42

Float Division
5.0

Integer Division (floor division)
5

Modulus (remainder)
1

Fibonacci
[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]

Factorial
120

Fibonacci

def fibonacci(n): #fibonacci sequence 
    fib_series = [0, 1]  

    while len(fib_series) < n:
        next_number = fib_series[-1] + fib_series[-2]  
        fib_series.append(next_number)  

    return fib_series

n = 10  
result = fibonacci(n)
print(result)  # [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]

# initial length of list is 2 
# while length of list is less than amount of numbers we want in our final sequence
# add the last two numbers of the list 
# add this value to the end of the list 
# repeat until length of list reaches n

[0, 1, 1, 2, 3, 5, 8, 13, 21, 34]

Mini Lesson: If, Else Statements

num =0

if num > 0:
    print(str(num) + " is positive.")
elif num < 0:
    print(str(num) + " is negative.")
else:
    print(str(num) + " is zero.")

0 is zero.

Mini Lesson 2: For, While Loops

names = ["Alice", "Bob", "Charlie", "David", "Eve"]
for name in names:
    print(name)


num = 1
while num <= 5:
    print(num)
    num += 1

Alice
Bob
Charlie
David
Eve
1
2
3
4
5

Mini Lesson 3: Defining Function

def calculate_square(number):
    square = number * number
    return square #ends function 

result = calculate_square(5)
print(f"The square of 5 is {result}")

Mini Lesson 4: Input

variable1 = input("How old are you?")
print("You are " + variable1 + " years old")

You are asd years old

ACTIVITY 2: CALCULATOR

Create calculator function
Allow user to Choose 2 numbers and an operator
Perform specified operation based on input
Return result of calculation

##YOUR WORK HERE 
##Hint: Use if else statements, defining functions, input

# String Operations and Concatenation:

print("\nString Concatenation") #add together strings
str1 = "Hello"
str2 = "World"
result = str1 + " " + str2
print(result)  # "Hello World"

print("\nString Length") #length of string
text = "This is a sample text."
length = len(text)
print(length)  # 22

print("\nString Indexing and Slicing") #string slicing 
text = "Python"
first_char = text[0]
substring = text[2:5]
print(first_char)  # 'P'
print(substring)  # 'tho'


print("\nString Repetition (Repeating Strings)")
text = "Repeat "
result = text * 3
print(result)  # "Repeat Repeat Repeat "

# Palindrome Check Algorithm:

print("\nPalindrome Check Algorithm")

def is_palindrome(text):
    text = text.replace(" ", "").lower()
    return text == text[::-1] ## == will return boolean 

result1 = is_palindrome("racecar")
result2 = is_palindrome("Hello, World!")

print(result1)  # True
print(result2)  # False

String Concatenation
Hello World

String Length
22

String Indexing and Slicing
P
tho

String Repetition (Repeating Strings)
Repeat Repeat Repeat 

Palindrome Check Algorithm
True
False

ACTIVITY 3: COUNTING VOWELS

Create a function that takes a word as an input
Use a for loop to iterate through each character of a word
Check how many characters in a word contain vowels
Return vowel number

##YOUR WORK HERE

HOMEWORK

CREATE TEXT (string) ANALYZER:

criteria:

Accepts input from user
Counts total letters, numbers, spaces in a string
Counts number of vowels
Calculates average word length
Correctly displays: total # of characters (including spaces + numbers), total vowels, average word length

other criteria:
ensure that program handles upper and lowercase spelling
Test multiple inputs to ensure accuracy
Criteria for above 90%:
Add a unique program, function, or feature not specified by criterias

ACTIVITY 2 SOLUTION

# Accept user input for two numbers and an operator
num1 = float(input("Enter the first number: "))
operator = input("Enter an operator (+, -, *, /): ")
num2 = float(input("Enter the second number: "))

# Perform the specified operation and print the result
if operator == "+":
    result = num1 + num2
elif operator == "-":
    result = num1 - num2
elif operator == "*":
    result = num1 * num2
elif operator == "/":
    if num2 == 0:
        print("Error: Division by zero is not allowed.")
    else:
        result = num1 / num2
else:
    print("Error: Invalid operator.")

if operator in ["+", "-", "*", "/"]:
    print(result)

2.0

ACTIVITY 3 SOLUTION

vowel_count = 0
word = input("Enter a word: ")

for char in word:
    if char.lower() in "aeiou":
        vowel_count += 1 # vowelcount = vowelcount + 1

print(vowel_count)

# set initial count to 0 
# go through each letter of the word 
# if any of the letters in word matches aeiou 
# add one to vowel count 
# after no more characters to check 
# print amount of vowels in word