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Java

Posted by Michael Singleton
Michael Singleton
6,253 Points

Find adjacent numbers

What is the greatest product of four adjacent numbers in the same direction (up, down, left, right, or diagonally) in the 20×20 grid?

08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08 49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00 81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65 52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 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 03 45 02 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 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21 24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72 21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95 78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92 16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57 86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58 19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40 04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66 88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69 04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36 20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16 20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54 01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48

Steve Hunter
Steve Hunter
57,709 Points

That's quite something - not sure I can help.

How are these numbers stored? Do we have any other information on this?

Steve.

3 Answers

Michael Singleton
Michael Singleton
6,253 Points
Michael Singleton
Michael Singleton
6,253 Points

int variable = grid [][]{};

Steve Hunter
Steve Hunter
57,709 Points

Problem 11, right?

Michael Singleton
Michael Singleton
6,253 Points
Michael Singleton
Michael Singleton
6,253 Points

yes

Michael Singleton
Michael Singleton
6,253 Points
Michael Singleton
Michael Singleton
6,253 Points

this is what i have so far.

int max = 0; for (int x = 0; x < current.length; x++) { for (int a = 0; a < current[x].length; a++) { int n = Math.max(Math.max(checkHoris(current, x, a), checkVert(current, x, a)), Math.max(checkRD(current, x, a), checkLD(current, x, a)));

            if (n > max)
                max = n;
        }
    }
    completion(max);
}

public int checkVert(int[][] current, int x, int a) {
    if (x + 3 >= current.length)
        num = 1;
    for (int r = x; r <= x + 3; r++) {
        num *= current[r][a];
        return num;
    }
    return 0;
}

public int checkLD(int[][] current, int x, int a) {
    if (x + 3 >= current.length || a - 3 < 0) {
        num = 1;
        int r = x;
        int c = a;
        while (r <= x + 3 && c >= a - 3) {
            num *= current[r][c];
            r++;
            c--;
        }
        return num;
    }
    return 0;
}

public int checkRD(int[][] current, int x, int a) {
    if (x + 3 >= current.length || a + 3 >= current[x].length) {
        num = 1;
        int r = x;
        int c = a;
        while (c <= a + 3 && r <= x + 3) {
            num *= current[r][c];
            r++;
            c++;
        }
        return num;
    }
    return 0;
}

public int checkHoris(int[][] current, int x, int a) {
    if (a + 3 >= current[x].length) {
        int num = 1;
        for (int c = a; a <= a + 3; c++) {
            num *= current[x][c];
        }
        return num;
    }
    return 0;

}