getting Started
1. Sort:
Second, the date problem:
That is, find the difference in days between two dates, and find the length of the date interval bounded by two specific dates. The idea is to unify the original interval problem to the interval problem determined by the starting point. That is, when finding the difference in days between two specific dates, we subtract the difference in days between them and the date at the far point to get the difference in days between these two specific dates. It is also necessary to pay attention to the issue of leap years. When the number of the year is not divisible by 100, it is a leap year if it is divisible by 4, and it is also a leap year when it is divisible by 400.
An important tip:
You can enter it like this, I didn't know it before.