Merge pull request #418 from jojoo15/patch-36

优化 0738.单调递增的数字 python3

problems/0738.单调递增的数字.md

@@ -147,18 +147,15 @@ class Solution {
 
 
 Python：
-```python
+```python3
 class Solution:
     def monotoneIncreasingDigits(self, n: int) -> int:
-        strNum = list(str(n))
-        flag = len(strNum)
-        for i in range(len(strNum) - 1, 0, -1):
-            if int(strNum[i]) < int(strNum[i - 1]):
-                strNum[i - 1] = str(int(strNum[i - 1]) - 1)
-                flag = i
-        for i in range(flag, len(strNum)):
-            strNum[i] = '9'
-        return int("".join(strNum))
+        a = list(str(n))
+        for i in range(len(a)-1,0,-1):
+            if int(a[i]) < int(a[i-1]):
+                a[i-1] = str(int(a[i-1]) - 1)
+                a[i:] = '9' * (len(a) - i)  #python不需要设置flag值，直接按长度给9就好了
+        return int("".join(a)) 
 ```
 
 Go：