Create ReplaceTheSubstringForBalancedString.py

Author: DreamOfTheRedChamber

Python/TwoPointers/ReplaceTheSubstringForBalancedString.py

@@ -0,0 +1,33 @@
+# Definition for a binary tree node.
+import collections
+import heapq
+import unittest
+
+# Read about enumerate in python
+from collections import defaultdict
+from typing import List
+
+class ReplaceTheSubstringForBalancedString(unittest.TestCase):
+
+    def balancedString(self, s: str) -> int:
+
+        histogram = collections.Counter(s)
+        result = n = len(s)
+        left = 0
+        for right, rightValue in enumerate(s):
+            histogram[rightValue] -= 1
+            while left < n and all(n / 4 >= histogram[value] for value in "QWER"):
+                result = min(result, right - left + 1)
+                histogram[s[left]] += 1
+                left += 1
+
+        return result
+
+    def test_Leetcode(self):
+        self.assertEqual(0, self.balancedString("QWER"))
+        self.assertEqual(1, self.balancedString("QQWE"))
+        self.assertEqual(2, self.balancedString("QQQW"))
+        self.assertEqual(3, self.balancedString("QQQQ"))
+
+if __name__ == '__main__':
+    unittest.main()