Submission #1286055

#	Time	Username	Problem	Language	Result	Execution time	Memory
1286055		Faisal_Saqib	Collecting Stamps 3 (JOI20_ho_t3)	C++20	100 / 100	229 ms	135368 KiB

ho_t3

#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int N=210;
ll x[N],t[N],dp[N][N][N][2];
int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    ll n,l;
    cin>>n>>l;
    x[0]=0;
    x[n+1]=l;
    for(int i=1;i<=n;i++)
    {
        cin>>x[i];
    }
    for(int i=1;i<=n;i++)
    {
        cin>>t[i];
    }
    for(int i=0;i<=n+1;i++)
    {
        for(int j=0;j<=n+1;j++)
        {
            for(int k=0;k<=n+1;k++)
            {
                for(int p=0;p<2;p++)
                {
                    dp[i][j][k][p]=1e18;
                }
            }
        }
    }
    dp[0][n+1][0][0]=0;
    dp[0][n+1][0][1]=0;
    for(int k=0;k<=n+1;k++)
    {
        for(int i=0;i<=n+1;i++)
        {
            for(int j=n+1;j>=0;j--)
            {
                for(int tl=0;tl<2;tl++)
                {
                    // 0 
                    ll tm=dp[i][j][k][0];
                    if((i+1)<j)
                    {
                        dp[i+1][j][k][0]=min(dp[i+1][j][k][0],tm+x[i+1]-x[i]);
                        if((tm+x[i+1]-x[i])<=t[i+1])
                        {
                            dp[i+1][j][k+1][0]=min(dp[i+1][j][1+k][0],tm+x[i+1]-x[i]);
                        }
                    }
                    // i]   j-1 [j
                    if((j-1)>i)
                    {
                        ll dt=l-x[j-1]+x[i];
                        dp[i][j-1][k][1]=min(dp[i][j-1][k][1],tm+dt);
                        if((tm+dt)<=t[j-1])
                        {
                            dp[i][j-1][k+1][1]=min(dp[i][j-1][k+1][1],tm+dt);
                        }
                    }

                    tm=dp[i][j][k][1];
                    if((j-1)>i)
                    {
                        dp[i][j-1][k][1]=min(dp[i][j-1][k][1],tm+(x[j]-x[j-1]));
                        if((tm+(x[j]-x[j-1]))<=t[j-1])
                        {
                            dp[i][j-1][k+1][1]=min(dp[i][j-1][k+1][1],tm+(x[j]-x[j-1]));
                        }
                    }
                    if((i+1)<j)
                    {
                        ll dt=l-x[j]+x[i+1];
                        dp[i+1][j][k][0]=min(dp[i+1][j][k][0],tm+dt);
                        if((tm+dt)<=t[i+1])
                        {
                            dp[i+1][j][k+1][0]=min(dp[i+1][j][k+1][0],tm+dt);
                        }
                    }
                }
            }
        }
    }
    for(int k=n;k>=0;k--)
    {
        for(int i=0;i<=(n+1);i++)
        {
            for(int j=n+1;j>=0;j--)
            {
                for(int p=0;p<2;p++)
                {
                    if(dp[i][j][k][p]<1e18)
                    {
                        // cout<<i<<' '<<j<<' '<<k<<' '<<p<<' '<<dp[i][j][k][p]<<endl;;
                        cout<<k<<endl;
                        return 0;
                    }
                }
            }
        }
    }
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 75 / 75