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Submission #696535

# Submission time Handle Problem Language Result Execution time Memory
696535 2023-02-06T17:58:08 Z lucri Ruins 3 (JOI20_ruins3) C++17
58 / 100
 6000 ms 258616 KB 
#include <bits/stdc++.h>
#define MOD  1000000007
using namespace std;
map<int,int>ma;
long long putere(long long a,long long b)
{
    if(b==0)
        return 1;
    long long p=putere(a,b/2);
    p*=p;
    p%=MOD;
    if(b%2)
    {
        p*=a;
        p%=MOD;
    }
    return p;
}
int fact[610],comb[610][610];
void factorial()
{
    fact[0]=1;
    for(long long i=1;i<=600;++i)
        fact[i]=fact[i-1]*i%MOD;
}
long long combinari(long long n,long long m)
{
    long long ans=1;
    ans=fact[n];
    ans*=putere(fact[m],MOD-2);
    ans%=MOD;
    ans*=putere(fact[n-m],MOD-2);
    ans%=MOD;
    return ans;
}
short n,v[610];
int cod(short step,short nrstack,short ppoz,bool exista)
{
    return ((1LL*step*601+nrstack)*600+ppoz-1)*2+exista-1;
}
long long raspunde(short step,short nrstack,short ppoz,bool exista)
{
    if(ma.find(cod(step,nrstack,ppoz,exista))!=ma.end())
        return ma[cod(step,nrstack,ppoz,exista)];
    if(step==n)
    {
        ma[cod(step,nrstack,ppoz,exista)]=1;
        return 1;
    }
    int ans=0;
    short ramas=n-step-nrstack;
    short posibileInceput=v[ppoz]-1-(2*step-step+ppoz-1-nrstack);
    if(exista==false)
    {
        if(ramas>=3)
            ans=(1LL*ans+1LL*comb[ramas-1][2]*raspunde(step+1,nrstack+1,ppoz,false))%MOD;
        if(ramas>=2)
            ans=(1LL*ans+1LL*(ramas-1)*raspunde(step+1,nrstack+1,ppoz,true))%MOD;
        if(posibileInceput>=2&&nrstack>=1)
            ans=(1LL*ans+1LL*comb[posibileInceput][2]*raspunde(step+1,nrstack-1,ppoz,false))%MOD;
        if(posibileInceput&&nrstack>=1&&ramas>=1)
        {
            if(ramas-1)
                ans=(1LL*ans+1LL*posibileInceput*(ramas-1)%MOD*raspunde(step+1,nrstack,ppoz,false))%MOD;
            ans=(1LL*ans+1LL*posibileInceput*raspunde(step+1,nrstack,ppoz,true))%MOD;
        }
        else if(posibileInceput&&ramas>=1)
        {
            if(step==n-1)
            {
                ma[cod(step,nrstack,ppoz,exista)]=1;
                return 1;
            }
            if(ramas-1)
                ans=(1LL*ans+1LL*posibileInceput*(ramas-1)%MOD*raspunde(step+1,nrstack,ppoz,false))%MOD;
            int q=putere(comb[n-ppoz][step+1-ppoz],MOD-2);
            for(int newppoz=ppoz+1;newppoz<=step+2;++newppoz)
                ans=(1LL*ans+1LL*comb[n-newppoz][step+2-newppoz]*q%MOD*posibileInceput%MOD*raspunde(step+1,nrstack,newppoz,false))%MOD;
        }
    }
    else
    {
        if(ramas>=2)
            ans=(1LL*ans+1LL*comb[ramas][2]*raspunde(step+1,nrstack+1,ppoz,true))%MOD;
        if(posibileInceput>=2)
        {
            if(nrstack>=2)
                ans=(1LL*ans+1LL*comb[posibileInceput][2]*raspunde(step+1,nrstack-1,ppoz,true))%MOD;
            else
            {
                if(step==n-1)
                {
                    ma[cod(step,nrstack,ppoz,exista)]=1;
                    return 1;
                }
                int q=putere(comb[n-ppoz][step+1-ppoz],MOD-2);
                for(int newppoz=ppoz+1;newppoz<=step+2;++newppoz)
                    ans=(1LL*ans+1LL*comb[n-newppoz][step+2-newppoz]*q%MOD*comb[posibileInceput][2]%MOD*raspunde(step+1,nrstack-1,newppoz,false))%MOD;
            }
        }
        if(posibileInceput&&ramas>=1)
            ans=(1LL*ans+1LL*posibileInceput*ramas%MOD*raspunde(step+1,nrstack,ppoz,true))%MOD;
    }
    ma[cod(step,nrstack,ppoz,exista)]=ans;
    return ans;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    factorial();
    cin>>n;
    for(int i=1;i<=n;++i)
        cin>>v[i];
    for(int i=0;i<=n;++i)
        for(int j=0;j<=i;++j)
            comb[i][j]=combinari(i,j);
    cout<<raspunde(0,0,1,false);
    return 0;
}

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 340 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct

Subtask #2
52.0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 340 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 12 ms 1140 KB Output is correct
12 Correct 10 ms 932 KB Output is correct
13 Correct 16 ms 1236 KB Output is correct
14 Correct 9 ms 988 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 2 ms 596 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 31 ms 2204 KB Output is correct
19 Correct 30 ms 2092 KB Output is correct
20 Correct 29 ms 2132 KB Output is correct

Subtask #3
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 0 ms 340 KB Output is correct
6 Correct 0 ms 340 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 12 ms 1140 KB Output is correct
12 Correct 10 ms 932 KB Output is correct
13 Correct 16 ms 1236 KB Output is correct
14 Correct 9 ms 988 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 2 ms 596 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 31 ms 2204 KB Output is correct
19 Correct 30 ms 2092 KB Output is correct
20 Correct 29 ms 2132 KB Output is correct
21 Correct 3439 ms 169736 KB Output is correct
22 Correct 2506 ms 134196 KB Output is correct
23 Correct 2507 ms 134032 KB Output is correct
24 Execution timed out 6075 ms 258616 KB Time limit exceeded
25 Halted 0 ms 0 KB -