3228. Maximum Number of Operations to Move Ones to the End

solve time: 28m 35s

Author: shyal

solved/p3228_Maximum_Number_of_Operations_to_Move_Ones_to_the_End_2025_11_13T10_09_25_743728_00_00Z.py

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+"""
+URL: https://leetcode.com/problems/maximum-number-of-operations-to-move-ones-to-the-end/description/?envType=problem-list-v2&envId=vn57k9wr
+
+3228. Maximum Number of Operations to Move Ones to the End
+
+You are given a binary string s.
+
+You can perform the following operation on the string any number of times:
+
+- Choose any index i from the string where i + 1 < s.length such that s[i] == '1' and s[i + 1] == '0'.
+- Move the character s[i] to the right until it reaches the end of the string or another '1'. For example, for s = "010010", if we choose i = 1, the resulting string will be s = "000110".
+
+Return the maximum number of operations that you can perform.
+
+Example 1:
+
+Input: s = "1001101"
+Output: 4
+Explanation:
+We can perform the following operations:
+- Choose index i = 0. The resulting string is "0011101".
+- Choose index i = 4. The resulting string is "0011011".
+- Choose index i = 3. The resulting string is "0010111".
+- Choose index i = 2. The resulting string is "0001111".
+
+Example 2:
+
+Input: s = "00111"
+Output: 0
+
+Constraints:
+- 1 <= s.length <= 10^5
+- s[i] is either '0' or '1'.
+
+---
+
+10 -> 01 == 1
+100 -> 001 == 1
+110 -> 011 == 2
+
+
+
+0011101
+
+Find the right most zero, and count the number of 1s to its left, + 1.
+
+"""
+
+
+class Solution:
+    def maxOperations(self, s: str) -> int:
+        s = s[::-1]
+        g = [[key, len(list(val))] for key, val in groupby(s)]
+        mult = 0
+        count = 0
+        for c, num in g:
+            if c == "1" and mult == 0:
+                continue
+            if c == "0":
+                mult += 1
+            elif c == "1":
+                count += mult * num
+        return count
+
+
+sol = Solution()
+
+# print(sol.maxOperations("1001101"))  # 4
+
+assert sol.maxOperations("1001101") == 4
+assert sol.maxOperations("00111") == 0
+assert sol.maxOperations("0") == 0
+assert sol.maxOperations("1") == 0
+assert sol.maxOperations("1010") == 3
+assert sol.maxOperations("01") == 0
+assert sol.maxOperations("010101") == 3
+assert sol.maxOperations("000") == 0
+assert sol.maxOperations("1111") == 0
+assert sol.maxOperations("10100") == 3
+# assert sol.maxOperations("1001") == 2
+
+assert sol.maxOperations("10") == 1
+assert sol.maxOperations("100") == 1
+assert sol.maxOperations("110") == 2
+assert sol.maxOperations("1110") == 3
+assert sol.maxOperations("101") == 1
+assert sol.maxOperations("00101") == 1
+assert sol.maxOperations("100000") == 1
+assert sol.maxOperations("01110") == 3
+assert sol.maxOperations("1100") == 2