C11ID - Mã số
Tác giả: flashmt
Ngôn ngữ: C++
#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
const int base = 1000000007;
int main()
{
int n,a[100100];
long long ans=1;
cin >> n;
for (int i=0;i<n;i++) scanf("%d",a+i);
sort(a,a+n);
for (int i=0;i<n;i++) ans=ans*(a[i]-i)%base;
cout << ans << endl;
}