其实就是问你数组里不同的元素能否超过二分之一。

不上描述了，上example吧

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.

class Solution {
    public int distributeCandies(int[] candies) {
        HashSet<Integer> set = new HashSet<Integer>();
        for(int i = 0;i<candies.length;i++)
        {
                set.add(candies[i]);
                
        }
        if(set.size()>=candies.length/2)
            return candies.length/2;
        return set.size();
    }
}