leetcode. 904. Fruit Into Baskets

Author: Partho Biswas

leetcode.com/python/#904 - Fruit Into Baskets.py

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+class Solution(object):
+
+    # outer for loop runs for all characters and the inner while loop processes each character only once,
+    # therefore the time complexity of the algorithm will be O(N+N) which is asymptotically equivalent to O(N)
+    # algorithm runs in constant space O(1)
+    def totalFruit(self, tree):
+        """
+        :type tree: List[int]
+        :rtype: int
+        """
+        return self.totalNumbberOfKFruit(tree, 2)
+
+    # maxFruitType is similar to number  of baskets where each baskets can contain only one type of fruit
+    def totalNumbberOfKFruit(self, tree, maxFruitType):
+        windowStart = 0
+        maxLength = 0
+        fruitFrequency = {}
+
+        # try to  extend the range [windowStart, windowEnd]
+        for windowEnd in range(len(tree)):
+            rightFruitType = tree[windowEnd]
+            if rightFruitType not in fruitFrequency:
+                fruitFrequency[rightFruitType] = 0
+            fruitFrequency[rightFruitType] += 1
+
+            # shrink the sliding window from the left side, until we are left with last 2 fruits
+            while len(fruitFrequency) > maxFruitType:
+                leftFruitType = tree[windowStart]
+                fruitFrequency[leftFruitType] -= 1
+                if fruitFrequency[leftFruitType] == 0:
+                    del fruitFrequency[leftFruitType]
+                windowStart += 1  # shrink the window
+            maxLength = max(maxLength, windowEnd - windowStart + 1)
+        return maxLength
+
+
+
+
+sol = Solution()
+input = [1,1,2,3,2,2,2]
+output = sol.totalFruit(input)
+print('Total Fruit: ', output)