Create 1758-MinimumChangesToMakeAlternatingBinaryString.py

Author: Jiezhi

src/1758-MinimumChangesToMakeAlternatingBinaryString.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+"""
+CREATED AT: 2022-11-29
+
+URL: https://leetcode.com/problems/minimum-changes-to-make-alternating-binary-string/
+
+GITHUB: https://github.com/Jiezhi/myleetcode
+
+FileName: 1758-MinimumChangesToMakeAlternatingBinaryString
+
+Difficulty: Easy
+
+Desc: 
+
+Tag: 
+
+See: 
+
+"""
+
+
+class Solution:
+    def minOperations(self, s: str) -> int:
+        """
+        1 <= s.length <= 10^4
+        s[i] is either '0' or '1'.
+        """
+        # ret1 for start with 0
+        # ret2 for start with 1
+        ret1, ret2 = 0, 0
+        for i, c in enumerate(s):
+            if i & 1:
+                if c == '1':
+                    ret2 += 1
+                else:
+                    ret1 += 1
+            elif c == '1':
+                ret1 += 1
+            else:
+                ret2 += 1
+        return min(ret1, ret2)
+
+
+def test():
+    assert Solution().minOperations(s="0100") == 1
+    assert Solution().minOperations(s="10") == 0
+    assert Solution().minOperations(s="1111") == 2
+
+
+if __name__ == '__main__':
+    test()