README_EN.md

2107. Number of Unique Flavors After Sharing K Candies

中文文档

Description

You are given a 0-indexed integer array candies, where candies[i] represents the flavor of the ith candy. Your mom wants you to share these candies with your little sister by giving her k consecutive candies, but you want to keep as many flavors of candies as possible.

Return the maximum number of unique flavors of candy you can keep after sharing with your sister.

 

Example 1:

Input: candies = [1,2,2,3,4,3], k = 3
Output: 3
Explanation: 
Give the candies in the range [1, 3] (inclusive) with flavors [2,2,3].
You can eat candies with flavors [1,4,3].
There are 3 unique flavors, so return 3.

Example 2:

Input: candies = [2,2,2,2,3,3], k = 2
Output: 2
Explanation: 
Give the candies in the range [3, 4] (inclusive) with flavors [2,3].
You can eat candies with flavors [2,2,2,3].
There are 2 unique flavors, so return 2.
Note that you can also share the candies with flavors [2,2] and eat the candies with flavors [2,2,3,3].

Example 3:

Input: candies = [2,4,5], k = 0
Output: 3
Explanation: 
You do not have to give any candies.
You can eat the candies with flavors [2,4,5].
There are 3 unique flavors, so return 3.

 

Constraints:

• 1 <= candies.length <= 105
• 1 <= candies[i] <= 105
• 0 <= k <= candies.length

Solutions

Python3

class Solution:
    def shareCandies(self, candies: List[int], k: int) -> int:
        cnt = Counter(candies[k:])
        ans = len(cnt)
        for i in range(k, len(candies)):
            cnt[candies[i]] -= 1
            cnt[candies[i - k]] += 1
            if cnt[candies[i]] == 0:
                cnt.pop(candies[i])
            ans = max(ans, len(cnt))
        return ans

Java

class Solution {
    public int shareCandies(int[] candies, int k) {
        Map<Integer, Integer> cnt = new HashMap<>();
        int n = candies.length;
        for (int i = k; i < n; ++i) {
            cnt.merge(candies[i], 1, Integer::sum);
        }
        int ans = cnt.size();
        for (int i = k; i < candies.length; ++i) {
            if (cnt.merge(candies[i], -1, Integer::sum) == 0) {
                cnt.remove(candies[i]);
            }
            cnt.merge(candies[i - k], 1, Integer::sum);
            ans = Math.max(ans, cnt.size());
        }
        return ans;
    }
}

C++

class Solution {
public:
    int shareCandies(vector<int>& candies, int k) {
        unordered_map<int, int> cnt;
        int n = candies.size();
        for (int i = k; i < n; ++i) {
            ++cnt[candies[i]];
        }
        int ans = cnt.size();
        for (int i = k; i < candies.size(); ++i) {
            if (--cnt[candies[i]] == 0) {
                cnt.erase(candies[i]);
            }
            ++cnt[candies[i - k]];
            ans = max(ans, (int) cnt.size());
        }
        return ans;
    }
};

Go

func shareCandies(candies []int, k int) (ans int) {
	cnt := map[int]int{}
	for _, c := range candies[k:] {
		cnt[c]++
	}
	ans = len(cnt)
	for i := k; i < len(candies); i++ {
		cnt[candies[i]]--
		if cnt[candies[i]] == 0 {
			delete(cnt, candies[i])
		}
		cnt[candies[i-k]]++
		ans = max(ans, len(cnt))
	}
	return
}

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

TypeScript

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