Welcome to Subscribe On Youtube

Formatted question description: https://leetcode.ca/all/1118.html

1118. Number of Days in a Month

Level

Easy

Description

Given a year Y and a month M, return how many days there are in that month.

Example 1:

Input: Y = 1992, M = 7

Output: 31

Example 2:

Input: Y = 2000, M = 2

Output: 29

Example 3:

Input: Y = 1900, M = 2

Output: 28

Note:

1. 1583 <= Y <= 2100
2. 1 <= M <= 12

Solution

If M is 1, 3, 5, 7, 8, 10, or 12, then there are 31 days in that month.

If M is 4, 6, 9, or 11, then there are 30 days in that month.

If M is 2, then Y needs to be checked whether it is a leap year. If Y is divisible by 4 but not divisible by 100, or Y is divisible by 400, then it is a leap year. There are 29 days in that month if it is a leap year or 28 days in that month otherwise.

• Java
• C++
• Python
• Go
• TypeScript

• class Solution {
      public int numberOfDays(int Y, int M) {
          if (M == 1 || M == 3 || M == 5 || M == 7 || M == 8 || M == 10 || M == 12)
              return 31;
          else if (M == 4 || M == 6 || M == 9 || M == 11)
              return 30;
          else {
              if (Y % 4 == 0 && Y % 100 != 0 || Y % 400 == 0)
                  return 29;
              else
                  return 28;
          }
      }
  }
  

• // OJ: https://leetcode.com/problems/number-of-days-in-a-month/
  // Time: O(1)
  // Space: O(1)
  class Solution {
      bool isLeapYear(int year) {
          return year % 4 == 0 && (year % 100 != 0 || year % 400 == 0);
      }
  public:
      int numberOfDays(int year, int month) {
          if (month == 2) return isLeapYear(year) ? 29 : 28;
          return month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12 ? 31 : 30;
      }
  };
  

• class Solution:
      def numberOfDays(self, year: int, month: int) -> int:
          leap = (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0)
          days = [0, 31, 29 if leap else 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
          return days[month]
  
  
  

• func numberOfDays(year int, month int) int {
  	leap := (year%4 == 0 && year%100 != 0) || (year%400 == 0)
  	x := 28
  	if leap {
  		x = 29
  	}
  	days := []int{0, 31, x, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}
  	return days[month]
  }
  

• function numberOfDays(year: number, month: number): number {
      const leap = (year % 4 === 0 && year % 100 !== 0) || year % 400 === 0;
      const days = [
          0,
          31,
          leap ? 29 : 28,
          31,
          30,
          31,
          30,
          31,
          31,
          30,
          31,
          30,
          31,
      ];
      return days[month];
  }
  
  

All Problems

All Solutions