How do I search for a number in a 2d array sorted left to right and top to bottom?

Question

I was recently given this interview question and I\'m curious what a good solution to it would be.

Say I\'m given a 2d array where all the numbers i

Answer 1

I think Here is the answer and it works for any kind of sorted matrix

bool findNum(int arr[][ARR_MAX],int xmin, int xmax, int ymin,int ymax,int key)
{
    if (xmin > xmax || ymin > ymax || xmax < xmin || ymax < ymin) return false;
    if ((xmin == xmax) && (ymin == ymax) && (arr[xmin][ymin] != key)) return false;
    if (arr[xmin][ymin] > key || arr[xmax][ymax] < key) return false;
    if (arr[xmin][ymin] == key || arr[xmax][ymax] == key) return true;

    int xnew = (xmin + xmax)/2;
    int ynew = (ymin + ymax)/2;

    if (arr[xnew][ynew] == key) return true;
    if (arr[xnew][ynew] < key)
    {
        if (findNum(arr,xnew+1,xmax,ymin,ymax,key))
            return true;
        return (findNum(arr,xmin,xmax,ynew+1,ymax,key));
    } else {
        if (findNum(arr,xmin,xnew-1,ymin,ymax,key))
            return true;
        return (findNum(arr,xmin,xmax,ymin,ynew-1,key));
    }
}