Number of Unique Flavors After Sharing K Candies

To solve this problem, we need to find the maximum number of unique flavors of candy we can keep after giving k consecutive candies to our little sister.

We can follow these steps to solve the problem:

  1. If k is 0, return the count of unique flavors in the entire candies array since we don’t have to share any candies.
  2. Initialize two pointers left and right both at the beginning of the array.
  3. Use a sliding window approach to iterate through the candies array. The window size will be k, representing the consecutive candies that will be shared.
  4. Keep track of the candy flavors inside the window using a Counter (or dictionary) and the flavors outside the window.
  5. Slide the window one step at a time, updating the counters for both inside and outside the window accordingly.
  6. At each step, calculate the number of unique flavors outside the window. Keep track of the maximum number found.
  7. Return the maximum number of unique flavors found outside the window.

Below is the code:

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from collections import Counter
from typing import List

class Solution:
    def shareCandies(self, candies: List[int], k: int) -> int:
        # Special case when k is 0
        if k == 0:
            return len(set(candies))

        # Initialize the pointers and counters for the candies inside and outside the window
        left = 0
        right = 0
        inside_window = Counter()
        outside_window = Counter(candies)

        # Initialize the maximum unique flavors
        max_unique_flavors = 0

        # Iterate through the candies array using the sliding window
        while right < len(candies):
            inside_window[candies[right]] += 1
            outside_window[candies[right]] -= 1
            if outside_window[candies[right]] == 0:
                del outside_window[candies[right]]

            # When the window size is k, update the maximum unique flavors and slide the window
            if right - left + 1 == k:
                max_unique_flavors = max(max_unique_flavors, len(outside_window))
                inside_window[candies[left]] -= 1
                if inside_window[candies[left]] == 0:
                    del inside_window[candies[left]]
                outside_window[candies[left]] += 1
                left += 1

            right += 1

        return max_unique_flavors

This code will return the correct answer for the given problem statement and handles all the edge cases.