Practice/Microsoft/Leetcode 1185. Day of the Week

Leetcode 1185. Day of the Week

CodingMust

Problem

You are given three integers representing a calendar date: the day of the month, the month number, and the year. Your task is to compute which day of the week that date corresponds to.

Return the name of the weekday as a string: "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", or "Saturday".

All input dates are guaranteed to be valid calendar dates within the range from January 1, 1971 to December 31, 2100, inclusive.

Requirements

1. Accept three integers: day (1-31), month (1-12), and year (1971-2100)
2. Return a string representing the day of the week
3. Handle leap years correctly (years divisible by 4 are leap years, except century years not divisible by 400)
4. The output must be one of the seven weekday names with proper capitalization

Constraints

• 1 ≤ day ≤ 31
• 1 ≤ month ≤ 12
• 1971 ≤ year ≤ 2100
• All input dates are valid (no invalid dates like February 30)
• O(1) time complexity expected
• O(1) space complexity expected

Examples

Example 1:

Input: day = 15, month = 8, year = 1995 Output: "Tuesday" Explanation: August 15, 1995 fell on a Tuesday.

Example 2:

Input: day = 29, month = 2, year = 2020 Output: "Saturday" Explanation: 2020 was a leap year, so February 29 existed and was a Saturday.

Example 3:

Input: day = 1, month = 1, year = 2000 Output: "Saturday" Explanation: The first day of the new millennium was a Saturday.