Leap year or not
Detailed guide and Python implementation for the 'Leap year or not' problem.
1. Concept Overview
The 'Leap year or not' problem is a key challenge in the Basics section.
This implementation focuses on easy-level logic in Python.
We prioritize technical accuracy and code readability in our provided solutions.
2. Real-World Applications
3. Visual Intuition
Visualizing the logic flow for Leap year or not.
4. Prerequisites
5. Step-by-Step Thinking
1. Understand the problem
Read the problem statement for Leap year or not carefully.
2. Formulate brute force
Draft a simple iterative solution.
3. Identify inefficiency
Look for redundant calculations.
4. Optimize search path
Use hashing or sorting to speed up the process.
5. Final Implementation
Clean up the code for production standards.
Problem Statement
Write a function is_leap_year(year) that takes an integer year and returns True if the year is a leap year, or False otherwise. A year is a leap year if it is divisible by 4 but not by 100, except when it is also divisible by 400.
- •1 <= year <= 10^5
Examples
year = 2024
True
2024 is divisible by 4 and not by 100, so it is a leap year.
year = 1900
False
1900 is divisible by 100 but not by 400, so it is not a leap year.
year = 2000
True
2000 is divisible by 400, so it is a leap year.
Need a Hint?
Edge Cases to Watch
- Empty input structures
- Single element inputs
- Large numerical bounds
Ready to Solve?
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Interview Insights & Variations
Complexity Analysis Breakdown
Why Time: Directly evaluates all possibilities.
Why Space: Uses standard local memory.
Why Time: Optimized paths reduce total operations.
Why Space: May trade memory for speed.
Optimized Solution Python Code
Optimized Solution Python Code
def is_leap_opt(year: int) -> bool:
# A year is a leap year if it is divisible by 4 but not by 100,
# except when it is also divisible by 400.
return (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0)Brute Force Code (Spoiler Guarded)
Brute Force Code (Spoiler Guarded)
def is_leap_brute(year: int) -> bool:
if year % 400 == 0:
return True
if year % 100 == 0:
return False
if year % 4 == 0:
return True
return FalseAlgorithm Pattern Checklist
When dealing with Basics data patterns.
Core Prerequisites
Revision Key Notes
Common Mistakes & Pitfalls
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