Submission #405539

#	Time	Username	Problem	Language	Result	Execution time	Memory
405539		sad	Cigle (COI21_cigle)	C++14	22 / 100	199 ms	255320 KiB

cigle

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define pb push_back
using namespace std;
int n;const int N=510,M=5009;
pair<int,int>dp[N][N];int a[N],fr[M],rw[N][N][N],prf[M];
pair<int,int>mxdp[N][N];
int main()
{
    cin>>n;int ans=0;
    for(int i=1;i<n+1;i++)cin>>a[i];
    for(int i=2;i<n;i++)
    {
        int sm=0;
        for(int j=i+1;j<n+1;j++)
        {
            if(j!=i+1)
            {
                sm+=a[j-1];
                fr[sm]=1;
            }

            int s=0,rs=0;
            for(int q=i-1;q>-1;q--)
            {
                if(q!=i-1)
                {
                    s+=a[q+2];
                    if(fr[s])
                        rs++;
                }
                rw[q][i][j]=rs;
            }

        }
        for(int j=n;j>i;j--)
        {
            if(j!=i+1)
            {
                fr[sm]=0;
                sm-=a[j-1];
            }
        }

    }
    for(int m=1;m<=n;m++)
    {
        memset(prf,-1,sizeof prf);
        int re=0;
        for(int i=m;i>0;i--)
        {
            re+=a[i];
            prf[re]=i;
        }
        re=0;
        dp[m][m]={0,n+1};
        mxdp[m][1]={dp[m][1].fi,1};
        for(int i=2;i<m;i++)
        {

            if(dp[m][i].fi>mxdp[m][i-1].fi)
            {
                mxdp[m][i]={dp[m][i].fi,i};continue;
            }
            mxdp[m][i]=mxdp[m][i-1];
        }
        dp[m+1][m]=mxdp[m][m-1];
        for(int r=m+2;r<n+1;r++)
        {re+=a[r-1];
            int last=dp[r-1][m].se;
            int mx=dp[r-1][m].fi;
            if(prf[re]==-1||prf[re]-2<0)
            {
                dp[r][m]=dp[r-1][m];
                ans=max(ans,dp[r][m].fi);continue;
            }
            if(last+2<=prf[re])
            {
                dp[r][m]={mx+1,last};
                ans=max(ans,dp[r][m].fi);continue;
            }
            pair<int,int>z=mxdp[m][prf[re]-2];
            z.fi+=rw[prf[re]-2][m][r];
            if(z.fi>mx)
            {
                dp[r][m]=z;
                ans=max(ans,z.fi);continue;
            }
            dp[r][m]=dp[r-1][m];
            ans=max(ans,dp[r][m].fi);
            continue;
        }
    }
    cout<<ans;

}
/*
10
2 3 2 1 1 5 5 2 5 1
*/

• Subtask 1: 9 / 9
• Subtask 2: 0 / 11
• Subtask 3: 13 / 13
• Subtask 4: 0 / 15
• Subtask 5: 0 / 52