Passport.pdf

/** https://leetcode.com/problems/unique-paths-ii/
 * @param {number[][]} obstacleGrid
 * @return {number}
 */
var uniquePathsWithObstacles = function(metrix) {
    var indx = {}
      , final_x = metrix.length - 1
      , final_y = metrix[0].length - 1;

    function getNext(x, y) {
        var solution = [];
        if (metrix[x + 1]) {
            metrix[x + 1][y] === 0 ? solution.push([x + 1, y]) : (indx[[x + 1, y]] = 0);
        }
        metrix[x][y + 1] === 0 ? solution.push([x, y + 1]) : (indx[[x, y + 1]] = 0);
        return solution;
    }

    function solve(cor_x, cor_y) {
        if (metrix[cor_x][cor_y] === 1) {
            indx[[cor_x, cor_y]] = 0;
            return 0;
        } else if (indx[[cor_x, cor_y]] >= 0 ) {
            return indx[[cor_x, cor_y]];
        }

        var nxt = getNext(cor_x, cor_y);

        if (nxt.length === 0) {
            if (cor_x === final_x && cor_y === final_y) {
                indx[[cor_x, cor_y]] = 1;
                return 1;
            } else {
                indx[[cor_x, cor_y]] = 0;
                return 0;
            }
        }

        var sol = 0;

        while (nxt.length > 0) {
            var elem = nxt.pop();
            sol += solve(elem[0], elem[1]);
        }

        indx[[cor_x, cor_y]] = sol;

        return sol;
    }

    if (metrix[0][0] === 1)
        return 0;

    if (metrix[metrix.length - 1][metrix[0].length - 1] === 1)
        return 0;

    solve(0, 0);

    return indx[[0, 0]];
};