Problem 11. Largest product in a grid

public class euler11 {
    public static void main(String[]args) {
        int[][] m = {
            {8,2,22,97,38,15,0,40,0,75,4,5,7,78,52,12,50,77,91,8},
            {49,49,99,40,17,81,18,57,60,87,17,40,98,43,69,48,4,56,62,0},
            {81,49,31,73,55,79,14,29,93,71,40,67,53,88,30,3,49,13,36,65},
            {52,70,95,23,4,60,11,42,69,24,68,56,1,32,56,71,37,2,36,91},
            {22,31,16,71,51,67,63,89,41,92,36,54,22,40,40,28,66,33,13,80},
            {24,47,32,60,99,3,45,2,44,75,33,53,78,36,84,20,35,17,12,50},
            {32,98,81,28,64,23,67,10,26,38,40,67,59,54,70,66,18,38,64,70},
            {67,26,20,68,2,62,12,20,95,63,94,39,63,8,40,91,66,49,94,21},
            {24,55,58,5,66,73,99,26,97,17,78,78,96,83,14,88,34,89,63,72},
            {21,36,23,9,75,0,76,44,20,45,35,14,00,61,33,97,34,31,33,95},
            {78,17,53,28,22,75,31,67,15,94,3,80,4,62,16,14,9,53,56,92},
            {16,39,5,42,96,35,31,47,55,58,88,24,0,17,54,24,36,29,85,57},
            {86,56,0,48,35,71,89,7,5,44,44,37,44,60,21,58,51,54,17,58},
            {19,80,81,68,5,94,47,69,28,73,92,13,86,52,17,77,4,89,55,40},
            {4,52,8,83,97,35,99,16,7,97,57,32,16,26,26,79,33,27,98,66},
            {88,36,68,87,57,62,20,72,3,46,33,67,46,55,12,32,63,93,53,69},
            {4,42,16,73,38,25,39,11,24,94,72,18,8,46,29,32,40,62,76,36},
            {20,69,36,41,72,30,23,88,34,62,99,69,82,67,59,85,74,4,36,16},
            {20,73,35,29,78,31,90,1,74,31,49,71,48,86,81,16,23,57,5,54},
            {1,70,54,71,83,51,54,69,16,92,33,48,61,43,52,1,89,19,67,48}
        };
        int pH = horizontal(m);
        int pV = vertical(m);
        int lR = leftToRight(m);
        int rL = rightToLeft(m);
        int max = 0;
        if (pH > max) {
            max = pH;
            if (pV > max) {
                max = pV;
                if (rL > max) {
                    max = rL;
                    if (lR > max)
                        max = lR;
                }
            }
        }
        System.out.println(max);
    }
    public static int horizontal(int[][]m) {
        int max = 0;
        int p = 1;
        for (int i = 0; i < 20; i++) {
            int k = 0;
            for (int j = 0; j < 17; j++) {
                int count = 0;
                k = j;
                while (count < 4) {
                    p *= m[i][k];
                    k++;
                    count++;
               	}
                if (max < p) 
                    max = p;
                p = 1;
            }
            if (max < p) 
                max = p;
                    p = 1;
        }
        return max;
    }
    public static int vertical(int[][]m) {
        int max = 0;
        int p = 1;
        for (int i = 0; i < 20; i++) {
            int k = 0;
            for (int j = 0; j < 17; j++) {
                int count = 0;
                k = j;
                while (count < 4) {
                    p *= m[k][i];
                    k++;
                    count++;
                }
                if (max < p) 
                    max = p;
                p = 1;
            }
            if (max < p) 
               	max = p;
            p = 1;
        }
        return max;
    }
    public static int leftToRight(int[][]m) {
        int max = 0;
        int p = 1;
        for (int i = 0; i < 17; i++) {
            int k = 0;
            for (int j = 0; j < 17; j++) {
                int count = 0;
               	k = j;
              	while (count < 4) {
            	    p *= m[k][k];
            	    k++;
		    count++;
              	}
                if (max < p) 
                    max = p;
                p = 1;
            }
            if (max < p) 
              	max = p;
            p = 1;
        }
       	return max;
    }
    public static int rightToLeft(int[][]m) {
        int max = 0;
        int p = 1;
        for (int i = 0; i < 17; i++) {
            for (int j = 0; j < 17; j++) {
                int l = i+3;
               	int count = 0;
             	int k = j;
            	while (count < 4) {
                    p *= m[l][k];
                    k++;l--;
                    count++;
                }
              	if (max < p) 
                    max = p;
                p = 1;
            }
            if (max < p) 
                max = p;
            p = 1;
        }
        return max;
    }
}