题解 | 计算阶乘

#include<bits/stdc++.h>
using namespace std;
#define int long long
const int MOD=1e9+7,N=1e6+10;
int T,n;
int f[N];

void solve(){
	
	if(f[n]!=0){
		cout<<f[n]<<endl;
		return;
	}
	
	int j=n;
	while(f[j]==0&&j>=1) j--;
	
	int sum=f[j]>=1?f[j]:1;j++;
	for(j;j<=n;j++){
		sum=sum*j%MOD;
		f[j]=sum;
	}
	
	cout<<f[n]<<endl;
	return;
}

signed main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	
	cin>>T;
	
	while(T--){
		cin>>n;
		
		solve();
	}

    return 0;
}