Submission #3877506

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(ll (i) = (0);(i) < (n);++i)
#define REV(i,n) for(ll (i) = (n) - 1;(i) >= 0;--i)
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define SHOW1d(v,n) {REP(WW,n)cerr << v[WW] << ' ';cerr << endl << endl;}
#define SHOW2d(v,WW,HH) {REP(W_,WW){REP(H_,HH)cerr << v[W_][H_] << ' ';cerr << endl;}cerr << endl;}
#define ALL(v) v.begin(),v.end()
#define Decimal fixed<<setprecision(20)
#define INF 1000000000
#define LLINF 1000000000000000000LL
#define MOD 1000000007

typedef long long ll;
typedef pair<ll,ll> P;

int main(){
	
	int n;cin >> n;
	vector<ll> A(n);REP(i,n)cin >> A[i];sort(ALL(A));
	vector<ll> B(n);REP(i,n)cin >> B[i];sort(ALL(B));
	vector<ll> num(n);
	
	ll ans = 1;
	ll AA = 0;
	ll cou = 0;
	
	REP(i,n){
		if(cou == 0 && A[cou] > B[i]){
			AA++;
			continue;
		}
		while(cou < n - 1 && A[cou+1] < B[i])cou++;
		num[cou]++;
	}
	
	//SHOW1d(num,n);
	
	cou = 0;
	REP(i,n){
		bool flag = true;
		cou++;
		if(AA > 0){
			ans *= AA;
			ans %= MOD;
			cou--;
			flag = false;
		}
		if(flag && num[i] > 0){
			ll tmp = 1;
			while(cou > 0 && num[i] > 0){
				tmp *= cou;
				tmp %= MOD;
				cou--;
				num[i]--;
			}
			ans *= tmp;
			ans %= MOD;
		}
		AA += num[i];
	}
			
	cout << ans << endl;
	
	return 0;
}

Submission Info

Judge Result