CareerCup

start searching from top right corner(i.e, 1row last element) of square.
1. if element is lessa than current element go left
else go down(i.e next row same coloumn)

Started from the top-right corner after clarifying that the matrix will be a 2-d matrix and walked either left or down. I unfortunately screwed up on the big-O analysis.

What is a sorted matrix? is the last element of a row smaller than the first element of the next row? or each row is independently sorted?

Here is an algo that works pretty well, though it is weird why you would ever want to do this. Probably more appropriately would be to hold this in a flat array and do a binary search on it, but I guess you can do sort of a multi-dimensional binary search. This should perform in O(log N) time.

static bool search(int [,] ints, int data)
        {
            int mid_1 = ints.Length / SIZE / 2;
            int mid_2 = mid_1;

            while (mid_1 >= 0 && mid_1 < ints.Length / SIZE)
            {
                if (ints[mid_1, mid_2] == data)
                    return true;

                if (ints[mid_1, mid_2] > data)
                {
                    for (int x = mid_2 - 1; x >= 0; x--)
                    {
                        if (ints[mid_1, x] == data)
                            return true;
                    }
                    mid_1--;
                }
                else
                {
                    for (int x = mid_2 + 1; x < ints.Length / SIZE; x++)
                    {
                        if (ints[mid_1, x] == data)
                            return true;
                    }
                    mid_1++;
                }
            }
            return false;
        }