[백준] 1931 - 회의실배정(설명X)

#include <iostream>
#include <algorithm>
using namespace std;
 
class Meeting {
private:
    int start, end;
public:
    bool operator<(Meeting m1) {
        if (this->end == m1.end)
            return this->start < m1.start;
        else
            return this->end < m1.end;
    }
    void set(int start, int end) {
        this->start = start;
        this->end = end;
    }
    int getEnd() { return end; }
    int getStart() { return start; }
};
 
int main() {
    int N, cnt = 0, criterion = 0;
    cin >> N;
    Meeting* meetings = new Meeting[N];
    for (int i = 0; i < N; i++) {
        int start, end;
        cin >> start >> end;
        meetings[i].set(start, end);
    }
    sort(meetings, meetings + N);
 
    for (int i = 0; i < N; i++) {
        if (criterion <= meetings[i].getStart()) {
            cnt++;
            criterion = meetings[i].getEnd();
        }
    }
    cout << cnt << endl;
}