Submission #1834351

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Source Code Expand

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;

struct INFO {
	int x, k;
	INFO(int x=0,int k=0):x(x),k(k){}

	bool operator<(const INFO& r)const {
		return x < r.x;
	}
};

#define MOD (int)(1e9+7)

int main() {
	int N; cin >> N;
	vector<INFO>AB(2 * N);
	for (int i = 0; i < N; i++) {
		int a; cin >> a;
		AB[i] = INFO(a, 0);
	}
	for (int i = 0; i < N; i++) {
		int b; cin >> b;
		AB[N+i] = INFO(b, 1);
	}

	sort(AB.begin(), AB.end());

	long long ans = 1;
	int m = AB[0].k;
	int cnt = 0;
	for (int i = 0; i < 2*N; i++) {
		if (AB[i].k == m) {
			cnt++;
		}
		else {
			if (cnt == 0) {
				m = AB[i].k;
				cnt++;
				continue;
			}

			ans *= cnt;
			ans %= MOD;
			cnt--;
		}
	}

	cout << ans << endl;

	return 0;
}

Submission Info

Judge Result