Leap Year - codepath/compsci_guides GitHub Wiki

Problem Highlights

• 🔗 Geeksforgeeks Link: [Leap Year]*(Insert Replit Link)
• 💡 Difficulty: Easy
• ⏰ Time to complete: 5 mins
• 🛠️ Topics: Functions
• 🗒️ Similar Questions: [Welcome to CodePath](Insert Replit Link)

1: U-nderstand

Understand what the interviewer is asking for by using test cases and questions about the problem.

• Established a set (2-3) of test cases to verify their own solution later.
• Established a set (1-2) of edge cases to verify their solution handles complexities.
• Have fully understood the problem and have no clarifying questions.
• Have you verified any Time/Space Constraints for this problem?

Given the function declaration, it tells us that we need to write a function that has one parameter. We’ll have to take in the parameter and determine if it is a leap year by using arithmetic operators. Based on the desired output, we’ll need to have one print statement.

• What arithmetic operators could we use to determine if a year is a leap year?
• What constitutes a leap year mathematically?
• Is the example output as expected?

Edge Cases: What happens is the domain of our answer (ie. what about year = 0?)

2: M-atch

Match what this problem looks like a function that expects a true or false return or a print statement.

(1) To determine if a year is a leap year, we will use the modulus operator to determine if the year is divisible by 4, 100, and 400.

(2) We will use if statements and conditionals to print the correct output.

3: P-lan

Plan the solution with appropriate visualizations and pseudocode.

Since we’re being passed in the year as a parameter, we can immediately use the variable year. We need to check the three conditions that make a leap year. If it divisible by 4, then we should check if it is divisible by 100. If it is, then it’s not a leap year. If it is divisible by 400, then it is. To determine if a number is divisible by another number, we can use the modulus operator. If it is divisible, then the modulus will equal 0. If the year is not divisible by 4 to begin with, then we don’t need to check any other condition and can print out that it is not a leap year In our print statement, we would use the year variable again to print any dynamic year that was passed into the function

4: I-mplement

Implement the code to solve the algorithm.

def is_leap_year(year: int):
  if year % 4 == 0:
    if year % 100 != 0 or year % 400 == 0:
      print(f"{year} is a leap year.")
    else:
      print(f"{year} is not a leap year.")
  else:
        print(f"{year} is not a leap year.")

5: R-eview

Review the code by running specific example(s) and recording values (watchlist) of your code's variables along the way.

• Trace through your code with an input to check for the expected output
• Catch possible edge cases and off-by-one errors

6: E-valuate

Evaluate the performance of your algorithm and state any strong/weak or future potential work.