leetcode算法课程第十周博客

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:

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].

分析：

在candies变量中，提供了两个有效信息，一个是糖果的总数，总数总是偶数个，这样哥哥和姐姐就能分到一样多的糖果，另一个信息是糖果的种类，因此我们总是偏向于给姐姐种类更多的糖果，用set得到种类的个数，和糖果总数的一般做比较，少的那个就是姐姐能分到的最大的糖果种数

源代码

class Solution {public:    int distributeCandies(vector<int>& candies) {        int length = candies.size();        int gainNums = length/2;        set<int> check;        for (int i = 0; i < length; i++) {            check.insert(candies[i]);        }        int kinds = check.size();        if (gainNums > kinds) {            return kinds;        } else {            return gainNums;        }    }};

运行结果