**Leetcode 729. My Calendar I | 区间覆盖

https://leetcode.com/problems/my-calendar-i/description/

leetcode上打heap标签的几个题用于练习数据结构都不错。

class MyCalendar {
public:
    MyCalendar() {
       
    }
    
    bool book(int start, int end) {
        auto a = this->mem.lower_bound( make_pair(start, end) );
        if (a != this->mem.end() && end > a->first ) {
            // cout << "afirst:" << a->first << " asecond:" << a->second << endl;
            return false;
        }
        if (a != this->mem.begin() && prev(a)->second > start) {
             // cout << "first:" << prev(a)->first << " second:" << prev(a)->second << endl;
             return false;
        }
        
        this->mem.insert( make_pair( start, end ) );
        
        return true;
    }
     // set< pair<int, int>, greater<  pair<int, int> > > mem;
    set< pair<int, int>  > mem;
    
};