int-and-integer

Integer and int Exercises

This directory contains exercises to help you practice working with Python integers. Unlike Java, Python has a unified int type that can handle both small and arbitrarily large numbers seamlessly.

Setup

1. Open your terminal/command prompt
2. Navigate to this directory
3. Run the exercises: python integers.py
4. Or work interactively: python3 -i integers.py

Exercises

Exercise 1: Basic Math Operations

Write a function calculate_sum(a, b) that returns the sum of two integers. Write a function calculate_product(a, b) that returns the product of two integers.

Exercise 2: Number Analysis

Write a function find_larger(a, b) that returns the larger of two integers. Write a function find_absolute_value(number) that returns the absolute value (always positive).

Exercise 3: Digit Operations

Write a function count_digits(number) that counts how many digits are in a positive integer. Write a function reverse_digits(number) that reverses the digits of a positive integer.

Exercise 4: Number Classification

Write a function is_prime(number) that returns True if the number is prime (only divisible by 1 and itself). Write a function is_perfect_square(number) that returns True if the number is a perfect square.

Exercise 5: Range Operations

Write a function sum_range(start, end) that calculates the sum of all integers from start to end (inclusive). Write a function count_multiples(number, limit) that counts how many multiples of number exist up to limit.

Exercise 6: Safe String Conversion

Write a function parse_int_safely(text) that tries to parse a string to int, returning None if it fails. Write a function int_to_binary(number) that converts an integer to its binary representation as a string.

Exercise 7: Mathematical Sequences

Write a function fibonacci(n) that returns the nth Fibonacci number (0, 1, 1, 2, 3, 5, 8, 13...). Write a function factorial(n) that calculates n! (n factorial).

Exercise 8: Number Base Conversion

Write a function to_binary_string(number) that converts an integer to its binary representation. Write a function from_binary_string(binary_str) that converts a binary string back to an integer.

Exercise 9: List Statistics

Write a function find_max(numbers) that finds the maximum value in a list. Write a function calculate_average(numbers) that calculates the average as a float.

Testing Your Code

After completing each exercise, test your functions with different inputs:

# Example tests
print(calculate_sum(5, 3))          # Should return 8
print(find_larger(10, 7))           # Should return 10
print(count_digits(12345))          # Should return 5
print(is_prime(17))                 # Should return True
print(sum_range(1, 5))              # Should return 15 (1+2+3+4+5)
print(parse_int_safely("123"))      # Should return 123
print(parse_int_safely("abc"))      # Should return None
print(fibonacci(6))                 # Should return 8
print(to_binary_string(10))         # Should return "1010"
print(find_max([1, 5, 3, 9, 2]))    # Should return 9

Python Integer Features

• Arbitrary precision: Python integers can be as large as memory allows
• No separate long type: Unlike older languages, Python 3 has unified int
• Automatic type promotion: Operations between int and float return float
• Boolean context: 0 is falsy, all other integers are truthy
• Bitwise operations: &, |, ^, ~, <<, >> for binary manipulation
• Built-in functions: abs(), min(), max(), sum(), divmod()

Tips

• Python integers have unlimited precision - no overflow concerns
• Use isinstance(x, int) to check if something is an integer
• // for integer division, / for float division
• ** for exponentiation (powers)
• Use range() for generating integer sequences
• f-strings are great for formatting: f"The answer is {number}"