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Submission #696533

# Submission time Handle Problem Language Result Execution time Memory
696533 2023-02-06T17:53:48 Z lucri Ruins 3 (JOI20_ruins3) C++17
58 / 100
 3218 ms 524288 KB 
#include <bits/stdc++.h>
#define MOD  1000000007
using namespace std;
unordered_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;
}
int n,v[610];
int cod(int step,int nrstack,int ppoz,bool exista)
{
    return ((step*601+nrstack)*600+ppoz-1)*2+exista-1;
}
long long raspunde(int step,int nrstack,int 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;
    int ramas=n-step-nrstack;
    int 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 224 KB Output is correct
2 Correct 0 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 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 0 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 224 KB Output is correct
2 Correct 0 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 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 0 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 4 ms 1108 KB Output is correct
12 Correct 3 ms 980 KB Output is correct
13 Correct 6 ms 1108 KB Output is correct
14 Correct 3 ms 1040 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 10 ms 1968 KB Output is correct
19 Correct 8 ms 1968 KB Output is correct
20 Correct 8 ms 1840 KB Output is correct

Subtask #3
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 224 KB Output is correct
2 Correct 0 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 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 0 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 4 ms 1108 KB Output is correct
12 Correct 3 ms 980 KB Output is correct
13 Correct 6 ms 1108 KB Output is correct
14 Correct 3 ms 1040 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 10 ms 1968 KB Output is correct
19 Correct 8 ms 1968 KB Output is correct
20 Correct 8 ms 1840 KB Output is correct
21 Correct 696 ms 163568 KB Output is correct
22 Correct 520 ms 113024 KB Output is correct
23 Correct 560 ms 112916 KB Output is correct
24 Correct 1002 ms 226780 KB Output is correct
25 Correct 78 ms 1720 KB Output is correct
26 Correct 76 ms 1792 KB Output is correct
27 Correct 76 ms 1704 KB Output is correct
28 Correct 125 ms 21116 KB Output is correct
29 Correct 75 ms 1720 KB Output is correct
30 Runtime error 3218 ms 524288 KB Execution killed with signal 9
31 Halted 0 ms 0 KB -