Easy
Write a program to count the number of days between two dates.
The two dates are given as strings, their format is YYYY-MM-DD
as shown in the examples.
Example 1:
Input: date1 = “2019-06-29”, date2 = “2019-06-30”
Output: 1
Example 2:
Input: date1 = “2020-01-15”, date2 = “2019-12-31”
Output: 15
Constraints:
1971
and 2100
.public class Solution {
public int daysBetweenDates(String date1, String date2) {
String[] strings1 = date1.split("-");
String[] strings2 = date2.split("-");
return Math.abs(
julianDay(
Integer.parseInt(strings1[0]),
Integer.parseInt(strings1[1]),
Integer.parseInt(strings1[2]))
- julianDay(
Integer.parseInt(strings2[0]),
Integer.parseInt(strings2[1]),
Integer.parseInt(strings2[2])));
}
private int julianDay(int year, int month, int day) {
int a = (14 - month) / 12;
int y = year + 4800 - a;
int m = month + 12 * a - 3;
return day + (153 * m + 2) / 5 + 365 * y + y / 4 - y / 100 + y / 400 - 32045;
}
}