[실1] 1931 - 회의실 배정

#include <iostream>
#include <algorithm>

using namespace std;

pair<int,int>arr[100001];

int main()
{
    int n,a,b,cnt=1;
    cin>>n;
    
    for (int i = 0; i < n; i++)
    {
        cin >> b >> a;
        arr[i] = {a, b};
    }
    sort(arr, arr + n); 
    int end=arr[0].first;
    
    for (int i = 1; i < n; i++)
    {
        if (end <= arr[i].second)
        { 
            cnt++;
            end = arr[i].first;
        }
    }
    cout<<cnt;
}