Connected Cell In a Grid - very good structured JavaScript code - use prototype, and ===, adjacent - neighbor nodes - an array

ConnectedCellInaGrid3.js

function toNumber(value){
    return parseInt(value.trim());
}

function Node(val, row, col){
    this.val = val;
    this.row = row;
    this.col = col;
    this.adjacent = [];
}

Node.prototype = {
    isAdjacent : function (node){
        var duplicates = this.adjacent.filter(function(adjacent){
            return adjacent === node;
        });
        return !!duplicates.length;
    },
    addAdjacent : function(node){
        if (!this.isAdjacent(node)){
            this.adjacent.push(node);
        }
    }
};

function Graph(data){
    this.data = data || [];
}

Graph.prototype = {
    addNode : function(node){
        this.data.push(node);
    },
    getNodesBy: function(condition){
        return this.data.filter(function(node){
            return condition(node);
        });
    }
};

function traverse(node){
    var count = 1;
    node.visited = true;
    node.adjacent.forEach(function(adjacent){
        if (!adjacent.visited){
            count += traverse(adjacent);
        }
    });
    return count;
}

function processData(input) {
    var lines = input.split("\n");
    var rows = toNumber(lines.shift());
    var cols = toNumber(lines.shift());
    var graph = new Graph();
    var rowStr = lines.slice(0, rows);
    var results = [];
    rowStr.forEach(function(val, row){
        val.trim().split(" ").slice(0, cols).forEach(function(val, col){
            if (toNumber(val) === 0){
                return;
            }
            var active = new Node(val, row, col);
            var neighbors = graph.getNodesBy(function(node){
                if (Math.abs(node.row - active.row) < 2 &&
                    Math.abs(node.col - active.col) < 2) {
                    return true;
                }
            });
            neighbors.forEach(function(node){
                active.code = node.code = node.code || active.code || Math.random() * 9999;
                node.addAdjacent(active);
                active.addAdjacent(node);
            });
            graph.addNode(active);
        });
    });
    graph.data.forEach(function(node){
        if (!node.visited){
            results.push(traverse(node));
        }
    });
    console.log(results.reduce(function(a, b){
        return a > b ? a : b;
    }));
}
process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
    _input += input;
});

process.stdin.on("end", function () {
   processData(_input);
});