2025-09-23 11:20

Status: adult

Tags: leetcode leetcode-medium strings arrays hash-maps google two-pointers sliding-window Leetcode

Fruit Into Baskets

Code

from collections import defaultdict
 
class Solution(object):
    def totalFruit(self, fruits):
        """
        :type fruits: List[int]
        :rtype: int
        """
 
    
        count = defaultdict(int)
        res, l, total = 0, 0, 0
        n = len(fruits)
 
        for r in range(n):
            count[fruits[r]] += 1
            total += 1
 
            while len(count) > 2:
                left_fruit = fruits[l]
                count[left_fruit] -= 1
                total -= 1
                l += 1
            
                if not count[left_fruit]:
                    count.pop(left_fruit)
 
            
            res = max(res, total)
        
        return res

Explanation

1. It uses a two pointer approach(sliding window). The problem wants us to find the longest contiguous subarray with 2 distinct elements

2. Use a sliding window with two pointers (l and r).

3. Expand r: add the fruit to count, increase window size.

4. If window has >2 types, shrink from l until only 2 remain.

5. Update res with the max window length.

6. Return res.

References

Neetcode