Leetcode_1456 solution

Author: Kondareddy1209

Leetcode/Leetcode_1456.py

@@ -0,0 +1,99 @@
+# max_vowels.py
+
+"""
+Problem:
+Find the maximum number of vowels in any substring of length k.
+
+This file includes:
+1. Brute Force Approach (for understanding)
+2. Sliding Window Approach (optimal)
+
+Author: Your Name
+"""
+
+class Solution:
+
+    # ------------------------------------------------------------
+    # 🔴 Method 1: Brute Force Approach (O(n * k))
+    # ------------------------------------------------------------
+    def maxVowels_bruteforce(self, s: str, k: int) -> int:
+        """
+        Logic:
+        - Check every substring of size k
+        - Count vowels in each substring
+        - Keep track of maximum
+        
+        Time Complexity: O(n * k)
+        Space Complexity: O(1)
+        """
+
+        vowels = {'a', 'e', 'i', 'o', 'u'}
+        max_count = 0
+
+        # Loop through all possible starting indices
+        for i in range(len(s) - k + 1):
+            count = 0
+
+            # Check substring of length k
+            for j in range(i, i + k):
+                if s[j] in vowels:
+                    count += 1
+
+            # Update maximum vowels found
+            max_count = max(max_count, count)
+
+        return max_count
+
+
+    # ------------------------------------------------------------
+    # 🟢 Method 2: Sliding Window Approach (O(n)) ✅ Optimal
+    # ------------------------------------------------------------
+    def maxVowels(self, s: str, k: int) -> int:
+        """
+        Logic:
+        - Maintain a window of size k
+        - Add right character (r)
+        - Remove left character (l) when window exceeds size k
+        - Track vowel count dynamically
+        
+        Time Complexity: O(n)
+        Space Complexity: O(1)
+        """
+
+        vowels = {'a', 'e', 'i', 'o', 'u'}
+        count = 0      # current number of vowels in window
+        max_count = 0  # result
+        l = 0          # left pointer
+
+        # Iterate through string using right pointer
+        for r in range(len(s)):
+
+            # Step 1: Add current character to window
+            if s[r] in vowels:
+                count += 1
+
+            # Step 2: If window size exceeds k, shrink from left
+            if r - l + 1 > k:
+                if s[l] in vowels:
+                    count -= 1
+                l += 1
+
+            # Step 3: If window size is exactly k, update answer
+            if r - l + 1 == k:
+                max_count = max(max_count, count)
+
+        return max_count
+
+
+# ------------------------------------------------------------
+# 🧪 Test the implementation
+# ------------------------------------------------------------
+if __name__ == "__main__":
+    sol = Solution()
+
+    s = "abciiidef"
+    k = 3
+
+    print("Input:", s, "k =", k)
+    print("Brute Force Output:", sol.maxVowels_bruteforce(s, k))
+    print("Sliding Window Output:", sol.maxVowels(s, k))