LeetCode-Distribute Candies

最新推荐文章于 2024-04-05 19:31:28 发布

BeHelium

最新推荐文章于 2024-04-05 19:31:28 发布

阅读量180

点赞数

CC 4.0 BY-SA版权

分类专栏： LeetCode 文章标签： LeetCode Java

本文链接：https://blog.youkuaiyun.com/qq_24133491/article/details/82963230

LeetCode 专栏收录该内容

306 篇文章

订阅专栏

本文探讨了一个有趣的问题：如何将不同种类的糖果均等分配给两人，以最大化每个人获得的糖果种类。通过使用哈希表记录糖果种类，文章提供了一种高效解决方案，并详细解释了其工作原理。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

Description：
Given an integer array with even length, where different numbers in this array represent different kinds of candies. Each number means one candy of the corresponding kind. You need to distribute these candies equally in number to brother and sister. Return the maximum number of kinds of candies the sister could gain.

Example 1:

Input: candies = [1,1,2,2,3,3]
Output: 3
Explanation:
There are three different kinds of candies (1, 2 and 3), and two candies for each kind.
Optimal distribution: The sister has candies [1,2,3] and the brother has candies [1,2,3], too. 
The sister has three different kinds of candies.

Example 2:

Input: candies = [1,1,2,3]
Output: 2
Explanation: For example, the sister has candies [2,3] and the brother has candies [1,1]. 
The sister has two different kinds of candies, the brother has only one kind of candies.

Note:

The length of the given array is in range [2, 10,000], and will be even.
The number in given array is in range [-100,000, 100,000].

题意：给定一个一维数组，数组中的元素表示糖果的种类，现要求将这些糖果均分给两个人，计算可分得的最多种类是多少；

解法：解题的关键是我们要知道现在一共有多少种类的糖果（可以用哈希表实现），一旦知道了有多少种类的糖果的情况下

如果糖果的种类 >= 给定数组的长度 / 2，那么我们可以分得的最多种类就是：给定数组的长度/2（均分情况下，可分得的最多数量糖果）
否则，我们可以分得得最多种类就是：此时糖果的种类

Java

class Solution {
    public int distributeCandies(int[] candies) {
        Map<Integer, Integer> table = new HashMap<>();
        for (int candy : candies) {
            table.put(candy, table.getOrDefault(candy, 0) + 1);
        }        
        return table.size() >= candies.length / 2 ?
            candies.length / 2 : table.size();
    }
}