This is equivalent to finding the "Longest Subarray with at most 2 Distinct Elements". We use a sliding window and a hash map to track the types of fruits in our baskets.

1. l = 0, res = 0, count = {}.
2. For each r:
   • count[fruits[r]] = count.get(fruits[r], 0) + 1.
   • While len(count) > 2:
     • count[fruits[l]] -= 1.
     • If count[fruits[l]] == 0, delete from map.
     • l += 1.
   • res = max(res, r - l + 1).
3. Return res.

• Time Complexity: O(N).
• Space Complexity: O(1) (map of size 3).

def total_fruit(fruits):
    count = {}
    l = 0
    res = 0
    for r in range(len(fruits)):
        count[fruits[r]] = 1 + count.get(fruits[r], 0)
        while len(count) > 2:
            count[fruits[l]] -= 1
            if count[fruits[l]] == 0:
                del count[fruits[l]]
            l += 1
        res = max(res, r - l + 1)
    return res