Submission #587955

#	Time	Username	Problem	Language	Result	Execution time	Memory
587955		Blagojce	Calvinball championship (CEOI15_teams)	C++11	0 / 100	41 ms	65536 KiB

teams

#include <bits/stdc++.h>
#define fr(i, n, m) for(int i = (n); i < (m); i ++)
#define st first
#define nd second
#define pq priority_queue
#define all(x) begin(x), end(x)

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;

const int mxn = 5005;
const ll  mod =  1000007;

int a[mxn];
int n;
	

ll dp[mxn][mxn];
ll C(int N, int K){
	if(N == 0) return 1;
	if(dp[N][K] == -1){
		dp[N][K] = C(N-1, K+1) + C(N-1, K)*K;
		dp[N][K] %= mod;
	}
	return dp[N][K];
}
	
int main(){
	memset(dp, -1, sizeof(dp));
	cin >> n;
	fr(i, 0, n){
		cin >> a[i];
	}
	
	int nxt = 2;
	ll ans = 1;
	fr(i, 0, n){
		
		int rem = n-i;
	
		ans += ((a[i]-1) * C(rem-1, nxt-1)) % mod;
		ans %= mod;
		if(a[i] == nxt){
			nxt++;
		}
	}
	cout<<ans<<endl;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 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