Ex14.2 - Lee

/**
 * Write a description of class Ex14 here.
 *
 * @author (your name)
 * @version (a version number or a date)
 */
public class Ex14
{
    private static final int DEFAULT_VAL = -1;

    public static int findMinDiff(int[] a, int x, int y)
    {
        int iX = DEFAULT_VAL;
        int iY = DEFAULT_VAL;
        int dist = DEFAULT_VAL;

        for(int i = 0; i < a.length; i++)
        {
            if(a[i] == x)
            {
                iX = i;
            }
            else if(a[i] == y)
            {
                iY = i;
            }

            if(iX != -1 && iY != -1)
            {
                dist = Math.abs(iX - iY);
            }
        }

        if(dist == DEFAULT_VAL)
        {
            return Integer.MAX_VALUE;
        }

        return dist;
    }

    public static boolean search(int[][] mat, int num)
    {
        int rL = 0, rH = mat.length;
        int cL = 0, cH = mat.length;
        int pR = rL + (rH - rL)/2;
        int pC = cL + (cH - cL) / 2;

        for(int i = 0; i < Math.log(mat.length)/Math.log(2); i++)
        {
            pR = rL + (rH - rL)/2;
            pC = cL + (cH - cL) / 2;
            if(num >= mat[pR][cL])
            {
                rL = pR;
                cH = pC;
            }
            else if(num >= mat[pR][pC])
            {
                rL = pR;
                cL = pC;
            }
            else if(num >= mat[rL][pC])
            {
                rH = pR;
                cL = pC;
            }
            else
            {
                rH = pR;
                cH = pC;
            }
        }

        pR = rL + (rH - rL)/2;
        pC = cL + (cH - cL) / 2;
        return mat[pR][pC] == num;
    }
}