[algogeeks] Max Arithmetic Subsequence

[Navneet Gupta]

I wrote the code as someone gave the reference of the paper where algo
to get max arithmetic subsequence was given.

For an input of {2,9,4,1,6,7,8,3,10}, i am getting an output of 3,
while it should be 5 for {2,4,6,8,10}

Below is the implementation, can someone help me understand where am i
going wrong?

int LongestArithmeticSubsequence(int *a, int len)
{
        int maxLen = 2;int i,k;
        int **L = (int **)new int[len];
        for(int m = 0; m <len; m++)
                L[m] = new int[len];
        for(int j = len - 1; j>=1;j--)
        {
                i = j-1;
                k = j+1;
                while(i>=1&&k<=len-1)
                {
                        if(a[i]+a[k]<2*a[j])
                                k++;
                        else if(a[i]+a[k]>2*a[j])
                        {
                                L[i][j] = 2;
                                i = i-1;
                        }
                        else
                        {
                                L[i][j] = L[j][k] + 1;
                                maxLen = getMax(maxLen, L[i][j]);
                                i = i-1; k = k+1;
                        }
                }
                while(i>=1)
                {
                        L[i][j] = 2;
                        i=i-1;
                }
        }
        return maxLen;
}

-- 
Regards,
Navneet

-- 
You received this message because you are subscribed to the Google Groups 
"Algorithm Geeks" group.
To post to this group, send email to algogeeks@googlegroups.com.
To unsubscribe from this group, send email to 
algogeeks+unsubscr...@googlegroups.com.
For more options, visit this group at 
http://groups.google.com/group/algogeeks?hl=en.