Submission #447652

#	Time	Username	Problem	Language	Result	Execution time	Memory
447652		minoum	Calvinball championship (CEOI15_teams)	C++17	20 / 100	20 ms	16100 KiB

teams

#include<bits/stdc++.h>

using namespace std;
typedef long long int ll;

#define int ll

const int MAXN = 1005, M2 = 2005;
const ll md = 1e9+7;

ll n, a[MAXN], pt = 0;
ll dp[MAXN][M2], ans = 0;

int32_t main()
{
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	for(int i = 1; i < M2; i++) dp[1][i] = i+1, dp[0][i] = 1ll;
	for(ll i = 2; i < MAXN; i++)
		for(ll j = 1; j < M2; j++){
			dp[i][j] = (j*dp[i-1][j])%md;
			if(j+1 < M2) dp[i][j] = (dp[i][j]+dp[i-1][j+1])%md;
		}
	cin >> n;
	for(int i = 0; i < n; i++) cin >> a[i];
	pt = 1;
	for(int i = 0; i < n; i++){
		if(a[i]==1) continue;
		ll tmp = (ll)a[i]-1ll;
		tmp = (tmp*dp[n-i-1][pt])%md;
		ans = (ans+tmp)%md;
		if(a[i]==pt+1) pt++;
	}
	cout << (ans+1)%md << '\n';
	return 0; 
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10