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OI-codes/Luogu/CF845C/CF845C.cpp

33 lines
717 B
C++

#include <bits/stdc++.h>
using namespace std;
bool cmp(pair<int, int> a, pair<int, int> b) {
return a.first == b.first ? a.second < b.second : a.first < b.first;
}
int main() {
int n;
pair<int, int> p[200005];
cin >> n;
for (int i = 0; i < n; i++) {
cin >> p[i].first >> p[i].second;
}
sort(p, p + n, cmp);
int tv1 = -1, tv2 = -1;
for (int i = 0; i < n; i++) {
if (p[i].first > tv1) {
tv1 = p[i].second;
} else {
if (p[i].first > tv2) {
tv2 = p[i].second;
} else {
cout << "NO" << endl;
return 0;
}
}
}
cout << "YES" << endl;
return 0;
}