I don't know why I get WA on test 4!
Can there be a negative number?
This is my code:

#include<iostream>
#include<cmath>
using namespace std;
long long dyn[110][510] , a[110][510] , big, sum[110][510] , p[110][510][2] , o , m, n;
int main(){
    cin>>m>>n;
    for(int i=0;i<m;i++)
        for(int j=0;j<n;j++)
           cin>>a[i][j];
    for(int i=0;i<m;i++)
    {
        sum[i][0]=a[i][0];
        dyn[i][0]=100000000000000000;
        for(int j=1;j<n;j++)
        {
            sum[i][j]=sum[i][j-1]+a[i][j];
            dyn[i][j]=100000000000000000;
        }
    }
if((m==1)&&(n==1))
{
cout<<1<<endl;
return 0;
}
    dyn[m-1][0]=a[m-1][0];
    for(int i=1;i<n;i++)
    {
        dyn[m-1][i]=a[m-1][i];
    }
    for(int i=m-2;i>=0;i--)
    {
        for(int j=n-1;j>=0;j--)
        {
            for(int k=0;k<n;k++)
            {
                if(j>k)
                {
                    if(dyn[i+1][k]+sum[i][j]-sum[i][k-1]<dyn[i][j])
                    {
                        dyn[i][j]=dyn[i+1][k]+sum[i][j]-sum[i][k-1];
                        p[i][j][0]=j;
                        p[i][j][1]=k;
                    }
                }
                else
                {
                    if(dyn[i+1][k]+sum[i][k]-sum[i][j-1]<dyn[i][j])
                    {
                        dyn[i][j]=dyn[i+1][k]+sum[i][k]-sum[i][j-1];
                        p[i][j][0]=j;
                        p[i][j][1]=k;
                    }
                }
            }
        }
    }
    big=dyn[0][0];
    o=0;
    for(int i=1;i<n;i++)
    {
        if(dyn[0][i]<big)
        {
            big=dyn[0][i];
            o=i;
        }
    }
    cout<<o+1;
    for(int i=1;i<m-1;i++)
    {
    if(p[i][o][0]<=p[i][o][1])
    {
        for(int j=p[i][o][0];j<=p[i][o][1];j++)
            cout<<" "<<j+1;
            }
            else
            {
            for(int j=p[i][o][0];j>=p[i][o][1];j--)
                cout<<" "<<j+1;
                }
            o=p[i][o][1];
    }
    cout<<" "<<o+1<<endl;
return 0;
}