gistfile1.txt

var assert = require('assert');

function rice_chessboard (A) {

    if (A.length === 0) return 0;
    if (A[0].length === 0) return 0;

    var count = A[0][0];

    var left_path = extract_sub(0, A);
    var right_path = extract_sub(1, A);

    console.log('paths');
    console.log(left_path);
    console.log(right_path);
    
    var left_total = rice_chessboard(left_path);
    var right_total = rice_chessboard(right_path);

    return count + ((left_total > right_total) ? left_total : right_total);

    function extract_sub(direction, matrix) {
	if (direction === 0) {
	    return matrix.slice(1, matrix.length);
	} else {
	    var sub = [];
	    for (var i = 0, len = matrix.length; i < len; i++) {
		sub.push(matrix[i].slice(1, matrix[i].length));
	    }
	    return sub;
	}
    }

}

var testMatrix = [
    [2, 2, 3, 0],
    [0, 3, 1, 1],
    [1, 2, 2, 1],
    [4, 1, 2, 2]
];
console.log('run');
var out = rice_chessboard(testMatrix);
console.log('out', out)
assert.equal(out, 15);