Submission #1008474

#	Time	Username	Problem	Language	Result	Execution time	Memory
1008474		ASN49K	Skyscraper (JOI16_skyscraper)	C++14	100 / 100	111 ms	5204 KiB

skyscraper

#include <bits/stdc++.h>
#define pb      push_back
#define all(x)  x.begin(),x.end()
using namespace std;
using i64 =long long;
#define int long long
const int mod=1e9+7;
const int inf=1e9;
const int N=100;
const int L=1'000;
int dp[2][N+2][L+1][3];
//nr de vecini liberi
void add_self(int& x,int y)
{
    x+=y;
    x%=mod;
}
int add(int x,int y)
{
    return (x+y)%mod;
}
int prod(int x,int y)
{
    return (1LL*x*y)%mod;
}
main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n,l;
    cin>>n>>l;
    if(n==1)
    {
        cout<<1<<'\n';
        return 0;
    }
    vector<int>a(n);
    for(auto &c:a)
    {
        cin>>c;
    }
    sort(all(a));
    a.pb(10000);
    dp[1][0][0][0]=1;
    for(int i=0;i<n;i++)
    {
        for(int j=1;j<=i+1;j++)
        {
            for(int cost=0;cost<=l;cost++)
            {
                for(int m=0;m<=2;m++)
                {
                    int& rez=dp[i&1][j][cost][m];
                    rez=0;

                    int old_cost=cost-(2*j-m)*(a[i+1]-a[i]);
                    if(old_cost<0)
                    {
                        continue;
                    }
                    //unim 2 comp
                    if(i==n-1)
                    {
                        add_self(rez , dp[(i&1)^1][j+1][old_cost][m]);
                    }
                    else
                    {
                        add_self(rez , prod((j+1-m)*j, dp[(i&1)^1][j+1][old_cost][m]));
                    }

                    //adaugam la un capat unei comp
                    //e capat
                    if(m>0)
                    {
                        //aici de gandit coef

                        if(m==1)add_self(rez , prod(2*j , dp[(i&1)^1][j][old_cost][m-1]));
                        else if(i==n-1)add_self(rez , dp[(i&1)^1][j][old_cost][m-1]);
                        else if(j>1)add_self(rez , prod(j-1 , dp[(i&1)^1][j][old_cost][m-1]));
                    }
                    add_self(rez , prod(2*j-m , dp[(i&1)^1][j][old_cost][m]));

                    //adaugam o noua componenta
                    add_self(rez , dp[(i&1)^1][j-1][old_cost][m]);
                    if(m>0)
                    {
                        add_self(rez , (3-m)*dp[(i&1)^1][j-1][old_cost][m-1]);
                    }
                }
            }
        }
        if(i==0)dp[1][0][0][0]=0;
    }
    int rez=0;
    for(int i=0;i<=l;i++)
    {
        add_self(rez , dp[(n&1)^1][1][i][2]);
    }
    cout<<rez;
}

Compilation message (stderr)

skyscraper.cpp:26:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   26 | main()
      | ^~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 80 / 80