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Submission #696546

# Submission time Handle Problem Language Result Execution time Memory
696546 2023-02-06T18:12:36 Z lucri Ruins 3 (JOI20_ruins3) C++17
58 / 100
 3459 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;
}
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 324 KB Output is correct
4 Correct 0 ms 324 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 1 ms 328 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 324 KB Output is correct
4 Correct 0 ms 324 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 1 ms 328 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 4 ms 1020 KB Output is correct
12 Correct 3 ms 980 KB Output is correct
13 Correct 5 ms 1108 KB Output is correct
14 Correct 5 ms 956 KB Output is correct
15 Correct 2 ms 456 KB Output is correct
16 Correct 2 ms 580 KB Output is correct
17 Correct 2 ms 468 KB Output is correct
18 Correct 9 ms 1968 KB Output is correct
19 Correct 9 ms 1864 KB Output is correct
20 Correct 11 ms 1840 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 324 KB Output is correct
4 Correct 0 ms 324 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 1 ms 328 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 4 ms 1020 KB Output is correct
12 Correct 3 ms 980 KB Output is correct
13 Correct 5 ms 1108 KB Output is correct
14 Correct 5 ms 956 KB Output is correct
15 Correct 2 ms 456 KB Output is correct
16 Correct 2 ms 580 KB Output is correct
17 Correct 2 ms 468 KB Output is correct
18 Correct 9 ms 1968 KB Output is correct
19 Correct 9 ms 1864 KB Output is correct
20 Correct 11 ms 1840 KB Output is correct
21 Correct 745 ms 163576 KB Output is correct
22 Correct 520 ms 113048 KB Output is correct
23 Correct 533 ms 112964 KB Output is correct
24 Correct 1039 ms 226860 KB Output is correct
25 Correct 75 ms 1780 KB Output is correct
26 Correct 74 ms 1784 KB Output is correct
27 Correct 75 ms 1748 KB Output is correct
28 Correct 123 ms 21156 KB Output is correct
29 Correct 74 ms 1740 KB Output is correct
30 Runtime error 3459 ms 524288 KB Execution killed with signal 9
31 Halted 0 ms 0 KB -