Searchin for an element in a sorted matrix

Hello everybody,

I have a n X n matrix. It is sorted row wise as well as column wise. Ex-

| 2 4 5 6|
| 3 9 11 12|
| 5 13 15 17|
| 8 14 19 50|

Now, if I want to find 12, what is most efficient algorithm to do that using Divide and conquer?

Can anybody please help?

thanks

hi i have a solution

check the elements diagonally, if u get it u have done it else find 2 ajacent elements in the diagonal such that a[i][i] < key < a[i+1][i=1] then divide matrix in 4 parts (like 4 quadrunts) out of which u may have ur key in the 2 parts and 2 parts rejected

Do apply the algorithm on remaining 2 matrices recursively.
and u get the answer


if u want i can write code for u.

thank u
bye.....