// Breadth-first search
// Port from:
// https://github.com/nature-of-code/NOC-S17-2-Intelligence-Learning/tree/master/week1-graphs/P2_six_degrees_kevin_bacon
// https://www.youtube.com/watch?v=piBq7VD0ZSo
// Hard to visualise graph
AB.headerRHS();
AB.newDiv("selectdiv");
$("#selectdiv").css({
"margin": "30",
});
$("#selectdiv").html(" Pick an actor: <span id='actorlist'></span> ");
const end_name = 'Kevin Bacon';
// Daniel Shiffman
// Nature of Code: Intelligence and Learning
// https://github.com/shiffman/NOC-S17-2-Intelligence-Learning
// Graph object
function Graph()
{
// store nodes by key and also in an array
this.graph = {};
this.nodes = [];
// Start and end
this.start = null;
this.end = null;
}
// Set the start
Graph.prototype.setStart = function(node)
{
this.start = node;
}
// Set the end
Graph.prototype.setEnd = function(node)
{
this.end = node;
}
// Add a node
Graph.prototype.addNode = function(label)
{
var n = new Node(label);
// Add to both the graph object and the nodes array
this.graph[label] = n;
this.nodes.push(n);
return n;
}
// Clear all searched and parent values
Graph.prototype.clear = function()
{
for (var i = 0; i < this.nodes.length; i++)
{
this.nodes[i].searched = false;
this.nodes[i].parent = null;
}
}
// Daniel Shiffman
// Nature of Code: Intelligence and Learning
// https://github.com/shiffman/NOC-S17-2-Intelligence-Learning
// Node object
function Node(label)
{
// Has a label
this.label = label;
// zero or more edges
this.edges = [];
// No parent and not searched by default
this.parent = null;
this.searched = false;
}
// Connect one or more neighbors
Node.prototype.connect = function(neighbor) // one Node (movie) has a connection to another Node (person)
{
// This is a fancy way of having a function
// that can accept a variable number of arguments
for (var i = 0; i < arguments.length; i++)
{
this.edges.push(arguments[i]); // increase the size of the array
// Connect both ways
arguments[i].edges.push(this);
}
}
// Daniel Shiffman
// Nature of Code: Intelligence and Learning
// https://github.com/shiffman/NOC-S17-2-Intelligence-Learning
// The data
var data;
// The graph
var graph;
// A lookup table for actors
// (redundant, the graph could handle this)
var actors;
// Dropdown menu for actors
var actorlist;
function preload()
{
data = loadJSON('/uploads/codingtrain/bacon.json');
}
function setup()
{
//RQ This is the setup. This sets up the canvas, and runs before a button is clicked
noCanvas();
// Create the graph
graph = new Graph();
// A separate lookup table for actors
actors = {};
// For all movies
var movies = data.movies;
for (var i = 0; i < movies.length; i++)
{
// Title and castlist
var movie = movies[i].title;
var cast = movies[i].cast;
// Add the movie to the graph
var movieNode = graph.addNode(movie); // Node movie
// Go through all the cast list
// console.log ("title and castlist setup for movie title " + movies[i].title);
// console.log ("and for cast " + movies[i].cast);
for (var j = 0; j < cast.length; j++)
{
var name = cast[j];
var actorNode;
// Does the actor exist already?
if (actors[name]) actorNode = actors[name];
// If not add a new node
else
{
actorNode = graph.addNode(name); // Node person
actors[name] = actorNode;
}
// Connect movie and actor
movieNode.connect(actorNode); // movie connects to person
}
}
// Create dropdown
actorlist = createSelect(); // https://p5js.org/reference/#/p5/createSelect
actorlist.parent('actorlist');
var allactors = Object.keys(actors);
// Add all the actors
for (var i = 0; i < allactors.length; i++)
actorlist.option(allactors[i]);
// Set up an event
actorlist.changed(findbacon);
}
function findbacon()
{
// RQ this function executes the once at runtime, once an actor is selected
// Clear everyone from having been searched
graph.clear();
// Start and end
var start = actors[actorlist.value()];
var end = actors[end_name];
graph.setStart(start);
graph.setEnd(end);
// Run the search!
bfs();
}
function bfs()
{
// Create a queue ad path
var queue = [];
var path = [];
//const end_name = 'Kevin Bacon';
//graph.setEnd(end);
// Get started
queue.push(graph.start);
//section of function up to this point executes once at runtime
while (queue.length > 0) // inside the loop we keep adding things to queue
{
var node = queue.shift(); // remove first item
console.log ("======" );
if (!node.searched) //RQ FIX if statement fix added here to check if a node has been already added to the queue, if it has, then it is not queued again
{
console.log ("start of search of " + node.label);
// Are we done?
if (node == graph.end)
{
console.log ("found goal node");
// Figure out the path
path.push(node);
var next = node.parent;
while (next)
{
path.push(next);
next = next.parent;
}
break;
}
else
{
console.log ("checking neighbours of " + node.label);
// Check all neighbors
var next = node.edges;
//console.log ("node.edges is " + node.edges);
//console.log ("end is " + end);
//str = JSON.stringify(end);
//str = JSON.stringify(end, null, 4); // (Optional) beautiful indented output.
//console.log("string version of end is " + str); // Logs output to dev tools console.
// if (node.edges==graph.end) //object1.name === object2.name
//{
// console.log ("found goal node1 " + neighbor.label + " breaking out of function");
// break;
// }
// console.log ("checking " + next.length + " neighbours");
for (var i = 0; i < next.length; i++)
{
var neighbor = next[i];
//RQ FIX Add in fix here to check for goal node and if it returns then exit
if (neighbor.label===end_name) //object1.name === object2.name
{
// console.log ("found goal node2 " + neighbor.label + " breaking out of function");
// break;
console.log ("found goal node "+neighbor.label); //print goal node to log
// Figure out the path
path.push(graph.end); //add the goal("Kevin Bacon") to the end of the path output on screen
path.push(node);
var next = node.parent;
while (next)
{
path.push(next);
next = next.parent;
}
//var skip_to_end='y'
break;
}
//console.log ("next[i].label is " + next[i].label);
//console.log ("neighbor.label " + neighbor.label);
//console.log ("graph.end " + graph.end);
// Any neighbor not already searched add to queue
// Any neighbor not already queued and searched add to queue
if (!neighbor.searched)
{
console.log ("adding unsearched neighbour " + neighbor.label + " to queue");
queue.push(neighbor);
// Update the parent
neighbor.parent = node;
// Mark node as searched
}
}
// Mark node as queued
//node.queue = true;
// Mark node as searched
node.searched = true;
console.log ("end of search of " + node.label);
// console.log ("======" );
}
}
} // end of while loop
// now output path
console.log('finished search for path');
// console.log ("path.length is " + path.length);
// path = bacon + movie + x + movie + x ... + movie + x
if (path.length===0) //RQ fix for path not found, if it is true, then print a "Path not found" messgae to output
{
// console.log('In the path not found if section');
var s='Path not found';
}
else
{
//console.log('In the standard closing else section');
var s = '<h1> Path length ' + path.length + '</h1>';
for (var i = path.length-1; i >= 0; i--)
{
if (i % 2 == 0) //RQ fix if statement to add highlighted text for the movie name
{
var path_highlight=path[i].label;
}
else
{
var path_highlight='<h4>'+path[i].label+'</h4>';
}
s = s + path_highlight +"<br>";
}
}
// "<p style='color:red'>"+ "</p>"+
AB.newDiv("theoutput");
$("#theoutput").css({
"margin": "30",
"padding": "30",
"display": "inline-block",
"border": "1px solid black"
});
// "font-weight": "900"
// "tr:odd": "#FF0000",
// "tr:even": "#00FF00"
// $("#theoutput tr:odd").css("background", "#FF0000");
//$("#theoutput tr:even").css("background", "#00FF00");
$("#theoutput").html(s);
}