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 ofkinds 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.

题目大意： 
给一个长度为偶数的整数数组，数组中不同数字都代表不同糖果，将糖果平均分给弟弟和妹妹，妹妹最多能得到几种糖果。

思路：

• 记录糖果种类，若糖果种类大于数组的一半，妹妹最多得到candies.size()/2种糖果,否则每种糖果都可以得到

int distributeCandies(vector<int>& candies) {
    int len=candies.size();
    sort(candies.begin(),candies.end());
    vector<int>::iterator iter1,iter2;
    iter1=unique(candies.begin(),candies.end());
    candies.erase(iter1,candies.end());
    int ans=0;
    //vector<int>::iterator iter1,iter2;
    for(iter2=candies.begin();iter2<candies.end();iter2++)
        ans++;
    return ans<=len/2?ans:len/2;
        
}

575. Distribute Candies