[BOJ] 냉장고

[BOJ] 냉장고

Problem URL : 냉장고

#include <iostream>
#include <algorithm>
#include <queue>
#define p pair<int,int>
using namespace std;
int n;

int main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> n;
    priority_queue<p, vector<p>, greater<p>> pq;

    for (int i = 0; i < n; i++) {
        int x, y; 
        cin >> x >> y;
        x += 270; y += 270;
        pq.push({ x,y });
    }
    int ans = 1;
    int pivot = pq.top().second;
    pq.pop();
    while (!pq.empty()) {
        int x = pq.top().first;
        int y = pq.top().second;
        pq.pop();
        if (x <= pivot) {
            pivot = min(pivot, y);
        }else {
            ans += 1; 
            pivot = y;
        }
    }
    cout << ans << endl;
}