leetcode 575. Distribute Candies

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].

为了得到种类最多，每次都抓新种类即可，但是最多不超过总数一半。

class Solution(object):
    def distributeCandies(self, candies):
        """
        :type candies: List[int]
        :rtype: int
        """
        # greedy        
        #return min(len(candies)/2, len(set(candies)))
        kinds = 0
        m = [0]*200001
        for c in candies:
            if not m[c+100000]:
                kinds += 1
                m[c+100000] = 1
        return min(len(candies)/2, kinds)                    

范围类的hash直接用数组即可。或者c++的bitset也行。