Submission #948347

#	Time	Username	Problem	Language	Result	Execution time	Memory
948347		Lilypad	Cryptography (NOI20_crypto)	C++14	48 / 100	1095 ms	7312 KiB

Crypto

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<ll,ll>
#define pb push_back
#define fi first
#define se second

const ll N = 3e5+3;
const ll MOD = 1e9+7;

ll a[N],b[N],fac[N];
ll n,tmp,ans;

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cin >> n;
	fac[0] = 1;
	for(int i=1; i<=n; i++) {
		cin >> a[i];
		b[i] = a[i];
		fac[i] = fac[i-1] * i;
		fac[i] %= MOD;
	}
//	sort(b+1,b+n+1);
//	for(int i=1; i<=n; i++) {
//		mp[b[i]] = i;
//	}
//	for(int i=1; i<=n; i++) a[i] = mp[a[i]];
	for(int i=1; i<=n; i++) {
		tmp = 0;
		for(int j=i+1; j<=n; j++) {
			if(a[i] > a[j]) tmp++;
		}
		ans += (fac[n-i] * tmp) % MOD;
		ans %= MOD;
	}
	cout << (ans + 1) % MOD << endl;
}

• Subtask 1: 5 / 5
• Subtask 2: 9 / 9
• Subtask 3: 0 / 10
• Subtask 4: 0 / 11
• Subtask 5: 21 / 21
• Subtask 6: 13 / 13
• Subtask 7: 0 / 19
• Subtask 8: 0 / 12