Offer_ prove safety review _ integer number 1 appears (the number of occurrences n is an integer from 1 to 1)

Integer number 1 appears

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https://blog.csdn.net/u010005281/article/details/80085255

# -*- coding:utf-8 -*-
class Solution:
    def NumberOf1Between1AndN_Solution(self, n):
        mult, sumTimes = 1, 0
        while n//mult > 0:
            high, mod = divmod(n, mult*10)
            curNum, low = divmod(mod, mult)
            if curNum > 1:
                sumTimes += high*mult + mult
            elif curNum == 1:
                sumTimes += high*mult + low + 1
            else:
                sumTimes += high*mult
            mult = mult*10
        return sumTimes