Leetcode 1004 answer

Author: Kondareddy1209

Leetcode/Leetcode_1004.py

@@ -0,0 +1,102 @@
+"""
+Problem: Max Consecutive Ones III (LeetCode)
+
+Goal:
+Given a binary array nums and an integer k,
+return the maximum number of consecutive 1s
+if you can flip at most k zeros.
+
+Concept:
+Sliding Window Technique
+
+---------------------------------------------------
+Approach 1: While Loop (Manual right pointer)
+---------------------------------------------------
+"""
+
+from typing import List
+
+
+class SolutionWhile:
+    def longestOnes(self, nums: List[int], k: int) -> int:
+        l = 0          # left pointer
+        r = 0          # right pointer
+        count = 0      # number of zeros in current window
+        ans = 0        # maximum length
+
+        while r < len(nums):
+            # Step 1: Expand window
+            if nums[r] == 0:
+                count += 1
+
+            # Step 2: Shrink window if invalid
+            while count > k:
+                if nums[l] == 0:
+                    count -= 1
+                l += 1
+
+            # Step 3: Update answer
+            ans = max(ans, r - l + 1)
+
+            # Step 4: Move right pointer
+            r += 1
+
+        return ans
+
+
+"""
+---------------------------------------------------
+Approach 2: For Loop (Cleaner and Recommended)
+---------------------------------------------------
+"""
+
+
+class SolutionFor:
+    def longestOnes(self, nums: List[int], k: int) -> int:
+        l = 0          # left pointer
+        count = 0      # number of zeros in current window
+        ans = 0        # maximum length
+
+        for r in range(len(nums)):
+            # Step 1: Expand window
+            if nums[r] == 0:
+                count += 1
+
+            # Step 2: Shrink window if invalid
+            while count > k:
+                if nums[l] == 0:
+                    count -= 1
+                l += 1
+
+            # Step 3: Update answer
+            ans = max(ans, r - l + 1)
+
+        return ans
+
+
+"""
+---------------------------------------------------
+Example Usage (for testing)
+---------------------------------------------------
+"""
+
+if __name__ == "__main__":
+    nums = [1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0]
+    k = 2
+
+    print("Using While Loop:", SolutionWhile().longestOnes(nums, k))
+    print("Using For Loop  :", SolutionFor().longestOnes(nums, k))
+
+
+"""
+---------------------------------------------------
+Key Takeaways:
+
+1. Sliding window expands using 'r'
+2. Shrinks using 'l' when condition breaks
+3. Maintain constraint: count of zeros <= k
+4. Time Complexity: O(n)
+5. Space Complexity: O(1)
+
+---------------------------------------------------
+"""