find cumulative sum of each column.
now for each arr[x][y] = sum of arr[i=0 to x] [j] ;

a1 b1 c1 d1
a2 b2 c2 d2
a3 b3 c3 d3
a4 d4 c4 d4

now we have reduced this problem to find max-subarray . which can
be efficiently calculated using kadane's algo for each row.

NOTE: now suppose if row = 0  does not participate in calculating max sum
matrix so u need to subtract a1 from a2,a3,a4 .... similarly for other
element in row 1,2,3.

now updated matrix considered i.e from (row =1 to row =3 ). for this
updated matrix,
 each[x][y] is the sum of arr[i=1 to x] [j].

similarly do for other elements.

On Mon, Jan 16, 2012 at 6:55 AM, Ashish Goel <ashg...@gmail.com> wrote:

> given a m*n matrix, find the subset rectangle with max sum (any other
> rectangle taken would have lesser sum)
> Best Regards
> Ashish Goel
> "Think positive and find fuel in failure"
> +919985813081
> +919966006652
>
> --
> 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.
>

-- 
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.

Reply via email to