[LeetCode] 575. Distribute Candies

轉自LeetCode

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:

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

<Solution>

想法如下

• 這題不困難，因為題目給的陣列一定會是偶數，所以重點放在計算有多少不同的糖果

• 可以利用 Set 的特性，來找出總共有多少種類的糖果

• 因為題目要求要平分，所以和陣列長度的一半做比較，回傳值較小的那一個就是答案

code 如下

Java