http://projecteuler.net/ - Problem 11

problem11.js

// Brute Force <3
var total   = 0,
    matrix  = [],
    numbers = "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".split(" ");

function buildMatrix() {
    for (var i = 0; i < 20; i++) {
        matrix.push(numbers.splice(0, 20));
    }
    findAdjacentNumbers();
}

function findAdjacentNumbers () {

    // Loop through all rows
    for (var i = 0; i < matrix.length; i++) {
        var row = matrix[i];
        
        // Loop through one row
        for (var j = 0; j < row.length; j++) {
            var num = row[j];
            
            // Left/Right
            if (j - 3 >= 0) {
                checkParts([row[j], row[j-1], row[j-2], row[j-3]]);
            }

            // 3 Rows Above
            if (i - 3 >= 0) {
                checkParts([num, matrix[i-1][j], matrix[i-2][j], matrix[i-3][j]]);

                // Up+Left Diag (we have 3 columns to the left)
                if (j >= 3) {
                    checkParts([num, matrix[i-1][j-1], matrix[i-2][j-2], matrix[i-3][j-3]]);
                }
                
                // Up+Right Diag (we have 3 columns to the right)
                if (j <= 16) {
                    checkParts([num, matrix[i-1][j+1], matrix[i-2][j+2], matrix[i-3][j+3]]);
                }

            }

        }
    }

    alert(total);
    
}

function checkParts(parts) {
    var totalOfParts = 1;
    for (var i = 0; i < parts.length; i++) {
        totalOfParts *= parts[i];
    }

    if (totalOfParts > total) {
        total = totalOfParts;
    }   
}

buildMatrix();