Century From Year（这年属于哪个世纪？）

Introduction
The first century spans from the year 1 up to and including the year 100, the second century - from the year 101 up to and including the year 200, etc.
Task
Given a year, return the century it is in.
Examples
1705 --> 18
1900 --> 19
1601 --> 17
2000 --> 20
Solution

def century(year): 
    return (year - 1) // 100 + 1
# 这里，// 表示整除，% 表示取余数。
# 例如，1705 // 100 = 17，1705 % 100 = 5，
# 所以 (1705 - 1) // 100 + 1 = 18。
# 1705表示第18个世纪