Submission #1003303

---

Source Code Expand

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <iostream>
#include <cassert>
#include <cmath>
#include <string>
#include <queue>
#include <set>
#include <map>
#include <cstdlib>
#include <cassert>

using namespace std;

#define TASKNAME ""

void solve(int test_number);

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.setf(ios::fixed);
    cout.precision(9);
    cerr.setf(ios::fixed);
    cerr.precision(3);
#ifdef LOCAL
    freopen("test.in", "r", stdin);
    freopen("test.out", "w", stdout);
#else
#endif
    int n = 1;
    for (int i = 0; i < n; i++) {
        solve(i);
    }
}

const int MAX_N = 200005;
const int MOD = 1000000007;


int n, a[MAX_N], b[MAX_N];

void solve(int test_number) {
    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
        scanf("%d", &a[i]);
    }
    for (int i = 0; i < n; i++) {
        scanf("%d", &b[i]);
    }
    sort(a, a + n);
    sort(b, b + n);
    long long ans = 1;
    int var = 0;
    int i = 0, j = 0;
    map<pair<int, int>, int> u;
    while (i < n || j < n) {
        if (u[make_pair(i, j)] > 2) {
            assert(false);
        }
        u[make_pair(i, j)]++;
        if (i < n) {
            while (j < n && b[j] <= a[i]) {
                var++;
                j++;
            }
        }
        if (var) {
            ans = ans * var % MOD;
            i++;
            var--;
        } else {
            swap(a, b);
            swap(i, j);
        }
    }
    printf("%lld\n", ans);
}

Submission Info

Judge Result