im not able to figure out the following problem. At point 1 I could either go to point 2 or point 5. From point to I could go to 3 or 4. From point 5 I could go to 6 or 7. From 7 there is only one path to 9. I would like to calculate all the full paths. Im not looking for the fastest route or anything. I need all the paths there are in a manner that I could follow them easily.
I have 2 questions:
Im not sure im using the correct way to 'store' the options (a[1]=[2,5]). Is this ok or is there a better way ?
Im not sure how to solve this. Can anyone give me a clue ? Im hoping im looking in the right direction :-)
The path:
1 ->2 ->3
->4
->5 ->6
->7 ->8 ->9
And the desired result:
1,2,3
1,2,4
1,5,6
1,5,7,8,9
My attempt at solving this in javascript
// this doesn't do what I need
var a = [];
a[1]=[2,5];
a[2]=[3,4];
a[5]=[6,7];
a[7]=[8];
a[8]=[9];
trytoloop(a,1);
function trytoloop(a,key){
if(a[key]){
for (var y in a[key]){
document.write(key);
trytoloop(a,a[key][y]);
}
} else {
document.write(key);
}
}
You do not keep track of the partial path you've built up so far. The array idea seems fine, though. Here's a working version with some more meaningful names: http://jsfiddle.net/YkH5b/.
// A cleaner way of defining the next keys
var nextKeysMap = {
1: [2, 5],
2: [3, 4],
5: [6, 7],
7: [8],
8: [9]
};
var fullPaths = [];
generateFullPaths([1], 1); // start off with partial path [1] and thus at key 1
function generateFullPaths(partialPath, currentKey) {
if(currentKey in nextKeysMap) { // can we go further?
var nextKeys = nextKeysMap[currentKey]; // all possible next keys
for (var i = 0; i < nextKeys.length; i++) { // loop over them
var nextKey = nextKeys[i];
// append the current key, and build the path further
generateFullPaths(partialPath.concat(nextKey), nextKey);
}
} else { // we cannot go further, so this is a full path
fullPaths.push(partialPath);
}
}
for(var i = 0; i < fullPaths.length; i++) {
console.log(fullPaths[i].join(","));
}
I put a solution below, but don't look if you don't want spoilers! It only deals with the case when there are no cycles in the graph.
Some hints without giving away the answer: I suggest that in your recursive function, you keep track of the whole path so far in the second argument, not just the current location, since otherwise you'll end up with a list of locations visited but how do you know the path that got you to each one? Second, in Javascript it's not considered good practice to iterate through an array with the for ... in construct, so you can use a regular for loop going from 0 to the length of the array. Thirdly, you're going to want to print the constructed path out at some point, but you don't want to do it at every step: instead, you want to print out the path when it's complete; that is, when there are no more places to go from the current location. Finally, I replaced document.write with console.log, since I believe document.write will overwrite the document contents each time you print something.
var a = [];
a[1]=[2,5];
a[2]=[3,4];
a[5]=[6,7];
a[7]=[8,9];
trytoloop(a,[1]);
function trytoloop(a,path){
var last = path[path.length - 1];
var next_hops = a[last];
// if there could be cycles, you might want to check that next_hops doesn't
// contain any already visited locations
if (next_hops) {
for (var i = 0; i < next_hops.length; i++) {
var new_path = path.concat([next_hops[i]]);
trytoloop(a, new_path);
}
} else {
console.log(path);
}
}
I haven't tried this, but off the top of my head, you could try something along these lines:
// use an object, and set the numbers as keys and the values as the child options
var a = {};
a[1] = {2:{3:{},4:{}},5:{6:{},7:{8:{9:{}}}}};
(function trytoloop(obj,num,str){
if(str.length>0) str += ',';
str += num
if(Object.keys(obj).length==0) document.writeln(str+'<br />');
else for(var key in obj) trytoloop(obj[key],key,str);
})(a[1],1,'');
Here's my solution: Fiddle
The final output it's going to the console, and you can change the initial node in here console.log(getPaths(1)); (starting from the node 1 according to your requirements).
Related
A little new to JS so be gentle :)
I'm trying to create a program that holds 5000+ boolean values that dynamically change based on other vars.
const chars = "abcdefghijklmnopqrstuvwxyz0";
const charsC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0"
const maxNum = 48;
const maxTile = 6;
var tile1, tile2, tile3, tile4, tile5, tile6
// test vars
var tile4 = "A27"
var t4a27 = false
// this snippet will be in an interval loop
for (let i = 1; i <= maxTile; ++i) {
for (let n = 0; n < chars.length; ++n) {
for (let j = 1; j <= maxNum; ++j) {
// this obviously doesnt work
var t[i][`${chars[n]}`][j];
// ^ ^ ^
if (tile[i] == `${charsC[n]}${j}`) {
t[i][h][j] = true;
console.log(t4a27)
} else {
t[i][h][j] = false;
}
}
}
}
For clarification a better word than "tile" for the vars could be "sprite" rather because its a point on the sprite.
The basic concept is the tile vars are designed to output their current position as a string value e.g. "A27". Then this loop will take that information and scan each tile subset to be true/false. So if the sprite lower right quadrant is inside "A27" the output would be t4a27 = true
In practice I can do this with just a lot of code (over 20,000 lines) but I figured their has to be an easier way that requires far less code.
This is probably not the right approach for your problem.
If you really need to store this amount of variables, it is probably best to put them in an object like so:
var tiles = {}
var tileName = 'abc'
// Dynamic setting:
tile[tileName] = true
// Dynamic reading:
console.log(tile[tileName])
I am wondering if you really want to store 5000 variables or if there is another way to calculate them at the time you need time, but that requires a bit more knowledge of the problem.
Javascript doesn't have this kind of ability to reflect local variables.
What you can do is attach all those variables to a global object, and proceed with: Object.keys(your_object) and your_object[key_name_here] = ...
I think you should use a 2-dim array for this. Or use a regular array of booleans with the appropriate size and do the index-magic yourself.
As you said, you are running on coordinates. A-27 is the same as row(1)+field(27) -- considering A is 1
If your field is 500x100, you create an Array as such: let gamefield = Array(500*100);
Warning: I have not tested this for syntax errors, but you should get the idea.
let gamefield = Array(500*100);
// optional gamefield.fill(true);
let row = idx => idx * 500;
let posIdx = (r, c) => row(r) + c;
// there is a sprite with a tiles property that returns
// 4 index positions for the sprite's quadrants as [r,c]
let quadrants = sprite.tiles.reportPositions()
// filter the quadrants where the gamefield at r,c is true
// this might also be a good case for some() instead of filter()
let collisions = quadrants.filter(pos => return gamefield[posIdx(...pos)]);
// if there is any of these, you can kill the sprite.
if(collisions.length > 0) sprite.kill();
I want to build an if statement in which the if criteria is based on an equality test of whether a variable equals any of several values. However, I do not want to hardcode the test values, but to pass an array of values that had been randomly subset earlier.
First, I get the set of randomized values by subsetting/sampling 5 values out of an array of 15 values. Basically, I'm using this excellent solution.
function getRandomSubarray(arr, size) {
var shuffled = arr.slice(0), i = arr.length, temp, index;
while (i--) {
index = Math.floor((i + 1) * Math.random());
temp = shuffled[index];
shuffled[index] = shuffled[i];
shuffled[i] = temp;
}
return shuffled.slice(0, size);
}
var x = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15];
var fiveRandomMembers = getRandomSubarray(x, 5);
Then, I want to pass fiveRandomMembers to test whether a variable is equal to any of the values in fiveRandomMembers's array. Then do something. To this end, I want to use this solution.
var L = function()
{
var obj = {};
for(var i=0; i<arguments.length; i++)
obj[arguments[i]] = null;
return obj;
};
if(foo in L(fiveRandomMembers)) {
/// do something
};
Unfortunately, this doesn't work for me. I must admit that the implementation of this code is within a Qualtrics survey, so the problem might be nuanced to the Qualtrics platform, and that's the reason it isn't working for me. I'm newbie to JavaScript so I apologize if this is a trivial question. But I believe that my code is problematic even in plain JavaScript (that is, regardless of Qualtrics), and I want to figure out why.
UPDATE 2020-05-24
I've been digging into this more deeply, and I have some insights. This looks more like a qualtrics problem rather than plain JS issue. However, the underlying problem might still have to do with some JS mechanism, and that's why I bother to update it here -- maybe someone will know what's causing this behavior.
To recap -- I want to condition an action based on whether a given variable's content matches either of the values in an array. I've tried using both includes and indexOf, but either method fails. The problem boils down to the functions not doing an exact match. For example, if I have an array of 5 numbers such as 8, 9, 12, 13, 14, and I want to test whether 4 exists in the array, then an exact match should return FALSE. However, both indexOf and contains return TRUE because 14 has 4 in it. This is not an exact matching then. Furthermore, I've tried to investigate what is the position indexOf would return for such a false-positive match. Typically, it would return a position that is even larger than the total length of the array, making no sense whatsoever. Here's an example from my Qualtrics survey, demonstrating the problem:
The code giving this is comprised of two qualtrics questions:
(-) First piece
Qualtrics.SurveyEngine.addOnReady(function()
{
/*Place your JavaScript here to run when the page is fully displayed*/
function getRandomSubarray(arr, size) {
var shuffled = arr.slice(0), i = arr.length, temp, index;
while (i--) {
index = Math.floor((i + 1) * Math.random());
temp = shuffled[index];
shuffled[index] = shuffled[i];
shuffled[i] = temp;
}
return shuffled.slice(0, size);
}
var x = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15];
var fiveRandomMembers = getRandomSubarray(x, 5);
if (Array.isArray(fiveRandomMembers)) Qualtrics.SurveyEngine.setEmbeddedData('is_array', "TRUE");
Qualtrics.SurveyEngine.setEmbeddedData('length', fiveRandomMembers.length);
Qualtrics.SurveyEngine.setEmbeddedData('five_sampled_numbers', fiveRandomMembers);
});
(-) Second piece
Qualtrics.SurveyEngine.addOnReady(function()
{
jQuery("#"+this.questionId).find('.QuestionText:first').css("padding-bottom", "0px");
var currentLoopNum = "${lm://CurrentLoopNumber}";
// var currentLoopNum = parseInt(currentLoopNum, 10); // tried converting to numeric but it doesn't solve the problem
var fiveSampledNumbers = "${e://Field/five_sampled_numbers}";
if (fiveSampledNumbers.includes(currentLoopNum)) {
Qualtrics.SurveyEngine.setEmbeddedData('does_loop_number_appear', "Yes");
} else {
Qualtrics.SurveyEngine.setEmbeddedData('does_loop_number_appear', "No");
}
Qualtrics.SurveyEngine.setEmbeddedData('index_of', fiveSampledNumbers.indexOf(currentLoopNum));
});
Here is a link to the Qualtrics survey, demonstrating the problem, in case it's helpful for troubleshooting: link
However, when testing the same code outside of Qualtrics, the problem doesn't replicate.
Does someone have a clue or even a hypothesis what could be the problem with the matching? Even if you're not necessarily familiar with Qualtrics...
I've never worked with Qualtrics before, but to me it is clear that the line
var fiveSampledNumbers = "${e://Field/five_sampled_numbers}";
will assign a string value to fiveSampledNumbers, not an array value.
Indeed, if you attempt to run the checks you are making on a string rather than an array, you get the unexpected results you saw above, because you are doing string operations rather than array operations:
var fiveSampledNumbers = "6,4,10,11,15";
console.log(fiveSampledNumbers.includes(5)); // logs true (string ends with the character "5")
console.log(fiveSampledNumbers.indexOf(5)); // logs 11 (index of the character "5")
To get around this, you will have to split the string by commas and parse each number within it:
var fiveSampledNumbers = "6,4,10,11,15";
fiveSampledNumbers = fiveSampledNumbers.split(",").map(function (n) { return parseInt(n, 10); });
console.log(fiveSampledNumbers.includes(5)); // logs false
console.log(fiveSampledNumbers.indexOf(5)); // logs -1
I'm working on an Extendscript tool for Adobe After Effects, and I'm trying to figure out one thing. Extendscript is just Javascript with some Adobe fluff added on top, but pretty much anything Javascript that isn't browser-specific works.
I have a script I've been using/developing for some time now which greatly simplifies importing thousands of images in image sequences. Everything is working great but there's one specific area that runs really slowly when you start getting into thousands of images and I'm trying to figure out how to speed it up.
What I am trying to optimize is going through an array of potentially thousands of image files, and concatenating it down to just the first image in the sequence. For example my array might be: [img.001.png, img.002.png, img.003.png, img.004.png, img.005.png] and what I want to do is remove every instance of "img.###.png" except for the first one. So after my function I would have just: [img.001.png].
Here's how I do it right now:
1) I take array item A, regex out the number sequence
2) then array item B, regex out the number sequence
3) and compare the two to see if they are identical. If they are I splice out item B
This works 100% of the time which is awesome, but is quite slow when you get above a thousand or two images... What I'm trying to do is find a way to do this "pruning" step more quickly. A friend of mine told me regex is pretty slow so maybe I need to do it without regex? I also found several native JavaScript array methods that might help such as forEach() every() and filter() but I don't see how these are going to be faster because I still need to do 2 regex evaluations, and I still need to compare the items to each other.
Any help would be immensely appreciated!
Spencer
Here's a snippet of my existing code:
currentFolder = new Folder ("//12.34.5.67/my folder on the network/")
var folderChildren = currentFolder.getFiles().sort();
var searcher = new RegExp("\\d{3,5}[.]");
for (var i = 0; i < folderChildren.length; i++) {
// Go through the array and strip out all elements that are the same once their numbers have been removed with a regex
if (i > 0) {
currentResult = searcher.exec(folderChildren[i].name); //check if a sequence
if (currentResult) { // it is a sequence
// first parse out the comparison strings - current item and item before
var testNameBefore = folderChildren[i-1].name;
//if we have a sequence before our current item, we need to delete the numbers.
var beforeNum = searcher.exec(testNameBefore);
if (beforeNum) {
testNameBefore = testNameBefore.substring(0, testNameBefore.length-8);
}
var testNameCurrent = folderChildren[i].name;
testNameCurrent = folderChildren[i].name.substring(0, testNameCurrent.length-8);
//compare to the element before it and delete if the same!!
if (testNameBefore == testNameCurrent) {
folderChildren.splice(i, 1);
i--;
}
}
}
}
You don't have a code snippet to compare, but this runs in just a few milliseconds.
var files = getFiles(),
cleanedFiles = getDesequencedArray(files);
console.log(`Parsing ${files.length} files.`);
console.log(`Found ${cleanedFiles.length} unique sequences:`);
console.log(cleanedFiles);
function getDesequencedArray(files) {
return files.reduce(
function(memo, file) {
var sequence = file.match(/(.*)\.?\d{3,5}(.*)/);
if (sequence) {
if (!memo.found[sequence[1] + sequence[2]]) {
memo.found[sequence[1] + sequence[2]] = 1;
memo.files.push(file);
}
} else {
//Did you want the other files included too?
//memo.files.push(file);
}
return memo;
}, {
found: {},
files: []
}
).files;
}
function getFiles() {
var files = [
"img1.001.jpg",
"img1.002.jpg",
"img1.001.png",
"img1.002.png",
"img1.003.png",
"img1.004.png",
"img2.011.jpg",
"img2.012.jpg",
"img2.013.jpg",
"img2.014.jpg",
"img300001.png",
"img300002.png",
"img300003.png",
"img300004.png",
"img300002.100.png",
"img300002.200.png",
"readme.md",
"index.html"
];
// Adding a bunch of records
for (let x = 0; x < 100; x++)
for (
let i = 1;
i <= 1000;
files.push(`img-${x}.` + ("00" + i++).substr(-3) + '.png')
);
return files;
}
I have a JSON response like this:
var errorLog = "[[\"comp\",\"Please add company name!\"],
[\"zip\",\"Please add zip code!\"],
...
Which I'm deserializing like this:
var log = jQuery.parseJSON(errorLog);
Now I can access elements like this:
log[1][1] > "Please add company name"
Question:
If I have the first value comp, is there a way to directly get the 2nd value by doing:
log[comp][1]
without looping through the whole array.
Thanks for help!
No. Unless the 'value' of the first array (maybe I should say, the first dimension, or the first row), is also it's key. That is, unless it is something like this:
log = {
'comp': 'Please add a company name'
.
.
.
}
Now, log['comp'] or log.comp is legal.
There are two was to do this, but neither avoids a loop. The first is to loop through the array each time you access the items:
var val = '';
for (var i = 0; i < errorLog.length; i++) {
if (errorLog[i][0] === "comp") {
val = errorLog[i][1];
break;
}
}
The other would be to work your array into an object and access it with object notation.
var errors = {};
for (var i = 0; i < errorLog.length; i++) {
errors[errorLog[i][0]] = errorLog[i][1];
}
You could then access the relevant value with errors.comp.
If you're only looking once, the first option is probably better. If you may look more than once, it's probably best to use the second system since (a) you only need to do the loop once, which is more efficient, (b) you don't repeat yourself with the looping code, (c) it's immediately obvious what you're trying to do.
No matter what you are going to loop through the array somehow even it is obscured for you a bit by tools like jQuery.
You could create an object from the array as has been suggested like this:
var objLookup = function(arr, search) {
var o = {}, i, l, first, second;
for (i=0, l=arr.length; i<l; i++) {
first = arr[i][0]; // These variables are for convenience and readability.
second = arr[i][1]; // The function could be rewritten without them.
o[first] = second;
}
return o[search];
}
But the faster solution would be to just loop through the array and return the value as soon as it is found:
var indexLookup = function(arr, search){
var index = -1, i, l;
for (i = 0, l = arr.length; i<l; i++) {
if (arr[i][0] === search) return arr[i][1];
}
return undefined;
}
You could then just use these functions like this in your code so that you don't have to have the looping in the middle of all your code:
var log = [
["comp","Please add company name!"],
["zip","Please add zip code!"]
];
objLookup(log, "zip"); // Please add zip code!
indexLookup(log, "comp"); // Please add company name!
Here is a jsfiddle that shows these in use.
Have you looked at jQuery's grep or inArray method?
See this discussion
Are there any jquery features to query multi-dimensional arrays in a similar fashion to the DOM?
I have been working on creating a custom script to help manage a secret questions form for a login page. I am trying to make all the seperate select lists dynamic, in that if a user selects a question in one, it will no longer be an option in the rest, and so on. Anyways, the problem I am having is when I try to set the variables in the other lists to null. I am currently working with only 3 lists, so I look at one list, and find/delete matches in the other 2 lists. Here is my loop for deleting any matches.
for(i=0; i<array1.length; i++) {
if(array2[i].value == txtbox1.value) {
document.questions.questions2.options[i] = null
}
if(array3[i].value == txtbox1.value) {
document.questions.questions3.options[i] = null
}
}
This works fine if both the matches are located at the same value/position in the array. But if one match is at array1[1] and the other match is at array3[7] for example, then only the first match gets deleted and not the second. Is there something I am missing? Any help is appreciated. Thanks!
I don't see too many choices here, considering that the position in each array can vary.
Do it in separate loops, unless of course you repeat values in both arrays and share the same position
EDTI I figured out a simple solution, it may work, create a function. How about a function wich recives an array as parameter.
Something like this:
function finder(var array[], var valueToFound, var question) {
for (i=0; i<array.lenght; i++) {
if (array[i].value == valueToFound) {
switch (question) {
case 1: document.questions.questions1.options[i] = null;
break;
}
return;
}
}
}
I think i make my point, perhaps it can take you in the right direction
My bet is that the code isn't getting to array3[7] because either it doesn't exist or that array2 is too short and you're getting a JavaScript exception that's stopping the code from doing the check. Is it possible that array2 and array3 are shorter than array1?
It is more code, but I would do it like this:
var selectedvalue == txtbox1.value;
for(i=0; i<array2.length; i++) { // iterate over the length of array2, not array1
if(array2[i].value == selectedvalue) {
document.questions.questions2.options[i] = null;
break; // found it, move on
}
}
for(i=0; i<array3.length; i++) {
if(array3[i].value == selectedvalue) {
document.questions.questions3.options[i] = null;
break; // you're done
}
}