Towers of Hanoi 2 - JavaScriptSource

See how you do in this wonderful game of skill and logic. Try to move all the disks onto another pole. Thing is, you can only move one disk at a time and you must follow size order (a bigger disk can’t go on a smaller disk). Good luck!

You must also upload all these necessary images to your website. Download this .zip file and upload the images to your web server.

Download hanoi.zip

Copy the coding into the BODY of your HTML document
Save all the hanoi images to your website directory

<!– STEP ONE: Paste this code into the BODY of your HTML document  –>

<BODY>

<SCRIPT LANGUAGE=”JavaScript”>
<!– Original:  Adam Stock ([email protected]) –>

<!– (c) Copyright 1998-99 Adam L. Stock. All Rights Reserved –>
<!– You have permission to republish this code provided –>
<!– that you do not remove this copyright notice –>

<!– This script and many more are available free online at –>
<!– The JavaScript Source!! http://javascriptsource.com –>

<!– STEP TWO: Save these images to your website server directory  –>

//   http://www.yourdomain.com/hanoi-img-directory/disk1.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk1h.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk2.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk2h.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk3.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk3h.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk4.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk4h.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk5.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk5h.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk6.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk6h.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk7.gif
//   http://www.yourdomain.com/hanoi-img-directory/disk7h.gif
//   http://www.yourdomain.com/hanoi-img-directory/post.gif
//   http://www.yourdomain.com/hanoi-img-directory/posttop.gif


// change this to where you upload the images to your site
imgdir = “http://www.your-web-site-address-here.com/images/your-hanoi-image-directory/”;


function preload() {
this.length = preload.arguments.length;
for (var i = 0; i < this.length; i++) {
this[i] = new Image();
this[i].src = imgdir + preload.arguments[i];
   }
}

var pics = new preload(“disk1.gif”,”disk2.gif”,
“disk3.gif”,”disk4.gif”,”disk5.gif”,”disk6.gif”,
“disk7.gif”,”pole.gif”, “disk1h.gif”,”disk2h.gif”,
“disk3h.gif”,”disk4h.gif”,”disk5h.gif”,”disk6h.gif”,
“disk7h.gif”);

var selectedr = null;
var selectedc = null;
var maxposts = 3;
var maxdisks = 7;
var all_posts = 3;
var startpost = 1;
var endpost = (startpost-1 < 0 ? maxposts-1 : startpost-1);
var disks = 7;
var imgwidth = 160;
var imgheight = 14;
var game_is_over = false;
var show_messages = false;
var board = new Array(maxposts);
board[0] = new Array(maxdisks + 1);
board[1] = new Array(maxdisks + 1);
board[2] = new Array(maxdisks + 1);

function initboard(startpost, disks) {
var len = board[0].length;
selectedc = null;
selectedr = null;
game_is_over = false;
endpost = (startpost-1 < 0 ? maxposts-1 : startpost-1);

for (i = 0; i < len; i++) {
board[0][i] = 0;
board[1][i] = 0;
board[2][i] = 0;
}
for (i = len-disks, j = 0; i < len; i++, j++) {
board[startpost][i] = len – j – 1;
   }
}

function drawall() {
for (j=0; j<board.length; j++) {
for (i=0; i<board[j].length; i++) {
draw(j,i, getName( board[j][i]));
   }
}
message(“You may begin! Select a piece to move.”);
}

function restart(start) {
startpost = start;
disks = document.forms[0].disc.options[document.forms[0].disc.selectedIndex].text;
initboard(startpost,disks);
drawall();
theAnim = new Animation();
}
initboard(startpost, disks);

function getName( num ) {
if (num == 0) return “post.gif”;
return “disk” + num + “.gif”;
}

function message(str, force) {
if (force || !game_is_over && !show_messages)
document.disp.message.value = str;
}

function messageadd(str) {
if (!game_is_over)
document.disp.message.value = document.disp.message.value + “n” + str;
}

function isempty(num) {
for (i = 0; i < board[num].length; i++) {
if ( board[num][i] != 0) return false;
}
return true;
}

function topmost(num) {
for (i = 0; i < board[num].length; i++) {
if (board[num][i] != 0) return  i;
}
return -1; 
}

function ispost(i,j) {
return (board[j][i] == 0);
}

function istopdisk(i,j) {
return (board[j][i-1] == 0);
}

function drawboard() {
document.writeln(“<h2>The Towers of Hanoi</h2><p>”);
document.writeln(“<table cellspacing=0 cellpadding=0 border=0>”);
document.write(“<tr>”);
for (j = 0; j < board.length; j++) {
document.write(“<td>”);
document.write(“<a href=’javascript:clicked(“+0+”,”+j+”)’><img src='” + imgdir + “posttop.gif’ border=0></a><br>”);
for (i=0; i< board[0].length; i++) {
document.write(“<a href=’javascript:clicked(“+i+”,”+j+”)’>”);
document.write(“<img src='” + imgdir + getName(board[j][i]) + “‘ name=’pos”+ j + i + “‘ border=0><br>”);
document.write(“</a>”);
}
document.writeln(“</td>”);
}
document.write(“</tr></table>”);
document.write(“<form name=’disp’><textarea name=’message’ wrap=virtual rows=2 cols=40></textarea><br>” + 
“Disks: <select name=”disc” size=1><option>3<option>4<option>5<option>6<option selected>7</select><input ”
+”type=button value=”Start the Game Over” onClick=”restart(startpost);”><input ”
+”type=button value=”Solve It!” onClick=”restart(startpost);setTimeout(‘hanoi(disks,startpost,endpost)’,300)”></form>”);
}

function draw(x,y,name) {
document.images[“pos”+x+””+y].src = imgdir + name;
}

function animate(x,y,name) {
theAnim.addFrame( “pos”+x+””+y, imgdir + name);
}

function clicked(i,j) {
document.forms[0].message.focus(); // get rid of annoying outline in MSIE
document.forms[0].message.blur();

if (game_is_over)  restart(startpost = endpost);
if (!isselection() && ispost(i,j)) { message(“Select a piece to move.”); return; }
if (!ispost(i,j)) { toggle(j); return; };
if (ispost(i,j) && selectedc == j) { message(“Move the piece to a different post.”); return; }
if (!legalmove(j)) { message(“That is not a legal move. Try again.”); return; }
move(j); return;
}

function legalmove(j) {
if (isempty(j)) return true;
return (board[j][topmost(j)] < board[selectedc][selectedr]);
}

function isselection() {
return selectedc != null;
}

function toggle( num ) {
var toppos = topmost(num);

if (selectedc == num && selectedr == toppos) {
selectedc = null; selectedr = null;
animate(num,toppos,”disk” + board[num][toppos] + “.gif”);
message(“Select a piece to move.”);
return;
}
if (isselection()) {
animate(selectedc,selectedr,”disk” + board[selectedc][selectedr] + “.gif”);
}
selectedc = num; selectedr = toppos;
animate(num,toppos,”disk” + board[num][toppos] + “h.gif”);
message(“Click on the post to which you want to move the disk.”);
}

function move( num ) {
var toppos = (!isempty(num) ? topmost(num) : board[num].length);
board[num][toppos-1] = board[selectedc][selectedr];
board[selectedc][selectedr] = 0;
animate(selectedc,selectedr,”post.gif”);
animate(num,toppos-1,”disk” + board[num][toppos-1] + “.gif”);
selectedc = null; selectedr = null;
message(“Select a piece to move.”);
game_over();
}

function hanoi(no_of_disks, start_post, goal_post) {
if (no_of_disks > 0) {
var free_post = all_posts – start_post – goal_post;
hanoi (no_of_disks – 1, start_post, free_post);
show_messages = true;
toggle(start_post);
move(goal_post);
show_messages = false;
hanoi (no_of_disks – 1 , free_post, goal_post);
game_over(true);
   }
}

function game_over(forceMsg) { 
var filledpost = null;
var val = 0;
for (k = 0; k < board.length; k++)  { 
val += ( isempty(k) ? 1 : 0 ); 
if (!isempty(k)) filledpost = k;
}

if (val == 2 && isempty(startpost)) {
message(“You won!”, forceMsg);
game_is_over = true;
endpost = filledpost;
}
return game_is_over;
}

//
// Animation functions
//

function Animation() {
this.imageNum = new Array();  // Array of indicies document.images to be changed
this.imageSrc = new Array();  // Array of new srcs for imageNum array
this.frameIndex = 0;          // the frame to play next
this.alreadyPlaying = false;  // semaphore to ensure we play smoothly

this.getFrameCount = getframecount;   // the total numebr of frame so far
this.moreFrames = moreframes;         // tells us if there are more frames to play
this.addFrame = addframe;             // add a frame to the animation
this.drawNextFrame = drawnextframe;   // draws the next frame
this.startAnimation = startanimation; // start the animation if necessary
}

function getframecount() {  return this.imageNum.length; }
function moreframes() {  return this.frameIndex < this.getFrameCount(); }
function startanimation() { 
if (!this.alreadyPlaying) {
theAnim.alreadyPlaying = true;
setTimeout(‘theAnim.drawNextFrame()’,5); 
   }
}

function addframe(num, src) {
var theIndex = theAnim.imageNum.length;
theAnim.imageSrc[theIndex] = src;
theAnim.imageNum[theIndex] = num;
theAnim.startAnimation();
}

function drawnextframe() {
if (theAnim.moreFrames()) {
document.images[ theAnim.imageNum[theAnim.frameIndex] ].src = theAnim.imageSrc[theAnim.frameIndex];
theAnim.frameIndex++;
setTimeout(‘theAnim.drawNextFrame()’, 30);
} else {
theAnim.alreadyPlaying = false;
   }
}

drawboard();
var theAnim = new Animation();
message(“You may begin! Select a piece to move.”);
document.disp.message.value = “”;
//  End –>
</script>

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</font></center><p>

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