题目链接

https://leetcode.cn/problems/monotone-increasing-digits/description/

代码

class Solution:
    def monotoneIncreasingDigits(self, n: int) -> int:
        strNum = str(n)
        flag = len(strNum)

        for i in range(len(strNum) - 1, 0, -1):
            if strNum[i] < strNum[i - 1]:
                flag = i
                strNum = strNum[:i - 1] + str(int(strNum[i - 1]) - 1) + strNum[i:]

        for i in range(flag, len(strNum)):
            strNum = strNum[:i] + '9' + strNum[i + 1:]

        return int(strNum)