记录编号	568952	评测结果	AAAAAAAAAA
题目名称	友好城市	最终得分	100
用户昵称	lihaoze	是否通过	通过
代码语言	C++	运行时间	0.000 s
提交时间	2022-02-11 00:41:45	内存使用	0.00 MiB

#include <iostream>
#include <algorithm>
#include <cstring>
#define fi first
#define se second
#define OPEN(_x) freopen(#_x".in", "r", stdin); freopen(#_x".out", "w", stdout)

using namespace std;
typedef pair<int, int> PII;

const int N = 2e5+10;
int n;
int p[N];
PII a[N];

int main() {
    OPEN(friendcity);
    ios::sync_with_stdio(false), cin.tie(0);
    cin >> n;
    for(register int i = 1; i<=n; ++i) cin >> a[i].fi >> a[i].se;
    sort(a+1, a+1+n, [&](PII _a, PII _b){return _a.se < _b.se;});
    int len = 0;
    p[0] = -2e9;
    for(register int i = 1; i<=n; ++i) {
        int l = 0, r = len;
        while(l < r) {
            int mid = l+r+1>>1;
            if(p[mid] < a[i].fi) l = mid;
            else r = mid-1;
        }
        p[r+1] = a[i].fi;
        len = max(len, r+1);
    }
    cout << len << '\n';
    return 0;
}