Submission #113015

#	Time	Username	Problem	Language	Result	Execution time	Memory
113015		ckodser	Calvinball championship (CEOI15_teams)	C++14	100 / 100	207 ms	696 KiB

teams

#include<bits/stdc++.h>

#define ll long long
#define pb push_back
#define mp make_pair
#define ld long double
#define F first
#define S second
#define pii pair<ll,ll> 

using namespace :: std;

const ll mod=1e6+7;
const ll maxn=10010;

ll a[maxn];
ll f[2][maxn];
ll mx[maxn];


inline void jam(ll &a,ll b){
    a+=b;
    if(a>=mod)a-=mod;
}

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    ll n;
    cin>>n;
    for(ll i=0;i<n;i++){
	cin>>a[i];
    }
    mx[0]=a[0];
    for(ll i=1;i<n;i++){
	mx[i]=max(mx[i-1],a[i]);
    }

    ll ans=1;
    for(ll i=0;i<maxn;i++){
	f[0][i]=1;
    }
    for(ll i=n-1;i>=1;i--){
	jam(ans,((a[i]-1)*f[(n-i-1)&1][mx[i-1]])%mod);

	bool no=(n-i)&1;
	bool la=(n-i-1)&1;
	
	for(ll j=0;j+1<maxn;j++){
	    f[no][j]=(f[la][j+1]+f[la][j]*j)%mod;
	}
    }
    cout<<ans;
}

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