Maximum 69 Number

Author: anantkaushik

1323-maximum-69-number.py

@@ -0,0 +1,39 @@
+"""
+Problem Link: https://leetcode.com/problems/maximum-69-number/
+
+Given a positive integer num consisting only of digits 6 and 9.
+Return the maximum number you can get by changing at most one digit (6 becomes 9, and 9 becomes 6).
+
+Example 1:
+Input: num = 9669
+Output: 9969
+Explanation: 
+Changing the first digit results in 6669.
+Changing the second digit results in 9969.
+Changing the third digit results in 9699.
+Changing the fourth digit results in 9666. 
+The maximum number is 9969.
+
+Example 2:
+Input: num = 9996
+Output: 9999
+Explanation: Changing the last digit 6 to 9 results in the maximum number.
+
+Example 3:
+Input: num = 9999
+Output: 9999
+Explanation: It is better not to apply any change.
+ 
+Constraints:
+1 <= num <= 10^4
+num's digits are 6 or 9.
+"""
+class Solution:
+    def maximum69Number (self, num: int) -> int:
+      six_index, i, temp = -1, 0, num
+      while temp > 0:
+        if temp % 10 == 6:
+          six_index = i
+        temp //= 10
+        i += 1
+      return (num + 3 *(10**six_index)) if six_index != -1 else num