414. Third Maximum Number

Posted 2020-11-28 habibah-chang

c++ STL

set容器

insert后的set是从小到大排序的。

 

set.begin() < .. < set.rbegin()

参考代码：

 1 class Solution {
 2 public:
 3     int thirdMax(vector<int>& nums) {
 4         set<int> MaxSet;
 5         for(int i=0; i<nums.size(); i++){
 6             MaxSet.insert(nums[i]);
 7             if(MaxSet.size()>3) MaxSet.erase(MaxSet.begin());
 8         }
 9         if(MaxSet.size()==3) return *MaxSet.begin();
10         else return *MaxSet.rbegin();
11     }
12 };