LeetCode in Kotlin
1185. Day of the Week
Easy
Given a date, return the corresponding day of the week for that date.
The input is given as three integers representing the day, month and year respectively.
Return the answer as one of the following values {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"}.
Example 1:
Input: day = 31, month = 8, year = 2019
Output: “Saturday”
Example 2:
Input: day = 18, month = 7, year = 1999
Output: “Sunday”
Example 3:
Input: day = 15, month = 8, year = 1993
Output: “Sunday”
Constraints:
- The given dates are valid dates between the years
1971and2100.
Solution
class Solution {
fun dayOfTheWeek(day: Int, month: Int, year: Int): String {
var counter = 0
for (i in 1971 until year) {
counter += if (isLeapYear(i)) {
366
} else {
365
}
}
for (i in 1 until month) {
counter += dayOfMonth(i)
}
for (i in 1..day) {
counter += 1
}
if (isLeapYear(year) && month > 2) {
counter++
}
return when (counter % 7) {
1 -> "Friday"
2 -> "Saturday"
3 -> "Sunday"
4 -> "Monday"
5 -> "Tuesday"
6 -> "Wednesday"
else -> "Thursday"
}
}
private fun isLeapYear(year: Int): Boolean {
return year % 4 == 0 && year % 100 != 0 || year % 400 == 0
}
private fun dayOfMonth(month: Int): Int {
return when (month) {
1, 3, 5, 7, 8, 10, 12 -> 31
4, 6, 9, 11 -> 30
else -> 28
}
}
}