597B - Restaurant - CodeForces Solution

#include <bits/stdc++.h>

using namespace std;
const int N = 5e5 + 7;
int n;
pair<int, int> p[N];
int main() {
    cin>>n;
    for(int i = 1; i <= n; i++) {
        int l, r;
        cin>>l>>r;
        p[i] = {r, l};
    }
    sort(p + 1, p + 1 + n);
    int cnt = p[1].first;
    int ans = 1;
    for(int i = 2; i <= n; i++) {
        if(p[i].second > cnt) {
            cnt = p[i].first;
            ans ++;
        }
    }
    cout << ans << '\n';
}/*1691312853.0849724*/