Develop Reference

How do I fix this cocktail shaker sort code to work?

I'm trying to write a code that sorts random numbers with different sorting alrorithms. I have 5 algorithms so far, including bubble sort, javascript built in sort, insertion sort, selection sort, and cocktail sort. I am also writing how many swaps and how much time each sort takes. Other sorts are working just fine( I think), but it seems like cocktail sort is not working.
I tried to modify that part of the code, but none of them worked. Here is the code below. I want it to work properly while displays how many swaps and how much time it took at the console. Thank you.
NUM_ELEMENTS = 500;
numbers = [];
function setup() {
createCanvas(400, 300);
for(i=0;i<=NUM_ELEMENTS;i++) {
numbers.push(round(random(1,NUM_ELEMENTS)));
}
para1 = createElement("p","");
tempString = "";
for(i=0;i<=NUM_ELEMENTS;i++) {
console.log(numbers[i]);
tempString = tempString + numbers[i] + ",";
}
para1.html(tempString);
button1 = createButton("Bubble Sort");
button1.mousePressed(bubbleSort);
button2 = createButton("Seclection Sort");
button2.mousePressed(selectionSort);
button3 = createButton("Insertion Sort");
button3.mousePressed(insertionSort);
button4 = createButton("Javascript Bulit-in Sort");
button4.mousePressed(bSort);
}
function bubbleSort() {
total = 0
swaps = 0
t1 = millis();
console.log("sorting")
let n = numbers.length;
for(let i = 0; i < n; i++) {
for(let j = 0; j < n; j++) {
if(numbers[j] > numbers[j+1]){
let t = numbers[j];
numbers[j] = numbers[j+1];
numbers[j+1] = t;
swaps = swaps + 1;
}
}
}
t2 = millis();
console.log(t2-t1);
console.log("swaps :",swaps);
}
function selectionSort() {
let n = numbers.length;
console.log("Sorting...")
total = 0
t1 = millis();
swaps = 0
for(let i = 0; i < n; i++) {
let min = i;
for(let j = i+1; j < n; j++){
if(numbers[j] < numbers[min]) {
min=j;
swaps = swaps + 1;
}
}
if (min != i) {
let tmp = numbers[i];
numbers[i] = numbers[min];
numbers[min] = tmp;
swaps = swaps + 1;
}
}
t2 = millis();
console.log(t2-t1);
console.log("swaps :", swaps);
}
function insertionSort() {
console.log("sorting");
t1 = millis();
swaps = 0;
total = 0
let n = numbers.length;
for (let i = 1; i < n; i++) {
let current = numbers[i];
let j = i-1;
while ((j > -1) && (current < numbers[j])) {
numbers[j+1] = numbers[j];
swaps = swaps + 1;
j--;
}
numbers[j+1] = current;
}
t2 = millis();
console.log(t2-t1);
console.log("swaps : ", swaps);
}
function bSort() {
console.log("Sorting...")
total = 0
t1 = millis();
sort(numbers);
t2 = millis();
console.log(t2-t1);
console.log("swaps : unknown");
}
function cocktailSort() {
console.log("sorting...")
total = 0
swaps = 0
t1 = millis();
let n = numbers.length;
let sorted = false;
while (!sorted) {
sorted = true;
for (let i = 0; i < n - 1; i++) {
if (numbers[i] > numbers[i + 1]){
let tmp = numbers[i];
numbers[i] = numbers[i + 1];
numbers[i+1] = tmp;
sorted = false;
}
}
if (sorted)
break;
sorted = true;
for (let j = n - 1; j > 0; j--) {
if (numbers[j-1] > numbers[j]) {
let tmp = numbers[j];
numbers[j] = numbers[j + 1];
numbers[j+1] = tmp;
sorted = false;
}
}
}
t2 = millis();
console.log(t2-t1);
}
function draw() {
background(220);
textSize(13);
column = 10;
row = 0;
for (i=0;i<NUM_ELEMENTS;i++) {
if (i%18==0) {
column = column + 18;
row = 0;
}
text(numbers[i],column,row*15+15);
row++;
}
}

Can't make pyramid of numbers

I Need to get this output:
1
2 3
4 5 6
7 8 9 10
11 12 13 14 15
What I've tried so far:
function getPyramid() {
let nums = 0;
for (let i = 1; i <= 15; i++) {
for (let n = 1; n < i; n++) {
console.log(n);
}
console.log('<br/>');
}
return nums;
}
getPyramid();

It is possible to do with one single loop
function getPyramid() {
let nums = 0;
let count = 1;
let numbers = ''
for (let i = 0; i <= 15; i++) {
if(count === nums){
count++
nums = 0;
console.log(numbers)
numbers = ''
}
nums ++
numbers += ' ' + (i +1)
}
}
getPyramid();
Or like this you can specify amount of rows..
function getPyramid(rows) {
let nums = 0;
let count = 1;
let numbers = ''
let i = 1
while (count < rows + 1 ) {
if(count === nums){
count++
nums = 0;
console.log(numbers)
numbers = ''
}
nums ++
numbers += ' ' + i
i++;
}
}
getPyramid(5);

for (let i = 1 ; i <= 5; i++)
{
let s = []
for (let x = i * (i - 1) / 2 + 1; x <= i * (i + 1) / 2; x++)
{
s.push(x)
}
console.log(s.join(" "))
}

Apart from notes given by jnpdx in the comments, I'd add some:
for better convention between programmers we tend to name varible nested in for-loop: i, j
<br/> for HTML new line, In JS we do \n for that!
number++ is same number += 1
Conditional_Operator (expression)?true:false instead of if/else
function getPyramid(Lines) {
let number = 1; // the counter to display on each line of pyramid!
for (let i = 1; i <= Lines; i++) {
let str = '';//line to display
for (let j = 1; j <= i; j++) {
str += number++;//incrementing counter
str += j!=i ? ' ' : ''; //to make space, but not at the end of line.
}
console.log(str);//display that line
}
}
getPyramid(5);

A completely unnecessary attempt to do this in a functional style:
const ranged_array = (from, to) =>
Array.from({ length: to - from + 1 }, (_, i) => i + from);
const pyramid = (lines) =>
ranged_array(1, lines)
.reduce((a, v, i) => {
const prev = a[i - 1];
const last_num = prev && prev[prev.length - 1] || 0;
a.push(ranged_array(last_num + 1, last_num + v));
return a;
}, [])
.map((v) => v.join(' '))
.join("\n");
console.log(pyramid(5));

JavaScript, JSON : how can I run a foor loop a specific amount of time?

I have this code - its a bit tricky:
let i = 0;
const inputBuffer = [];
const randomnumber = (min, max) => {
return Math.floor(Math.random() * (max - min + 1) + min);
}
for (let k = 0; k < 10; k++) {
console.log(convert(randomnumber(0, 1982)));
}
function convert(input) {
inputBuffer.push(input);
const output = {"current" : "0"};
if (i % 3 == 0) {
let sum = 0;
for (let ii = 0; ii < i; ii++) {
sum += inputBuffer[ii];
}
output.sum = sum;
}
i++;
output.current = input;
return JSON.stringify(output);
}
The output looks like this:
{"current":605,"sum":0}
{"current":708}
{"current":456}
{"current":1838,"sum":1769}
{"current":1619}
{"current":1404}
{"current":1068,"sum":6630}
{"current":1178}
{"current":989}
{"current":1280,"sum":9865}
But I want it to look like this:
{"current": 605}
{"current": 708}
{"current": 456}
{"current": 1838,"sum":1769}
{"current": 1619}
{"current": 1404}
{"current": 1068,"sum":6630}
{"current": 1178}
{"current": 989}
{"current": 1280,"sum":9865}
let i = 0;
const inputBuffer = [];
const randomnumber = (min, max) => {
return Math.floor(Math.random() * (max - min + 1) + min);
}
for (let k = 0; k < 10; k++) {
console.log(convert(randomnumber(0, 1982)));
}
function convert(input) {
inputBuffer.push(input);
const output = {
"current": "0"
};
if (i % 3 == 0) {
let sum = 0;
for (let ii = 0; ii < i; ii++) {
sum += inputBuffer[ii];
}
output.sum = sum;
}
i++;
output.current = input;
return JSON.stringify(output);
}
I don't want to show the sum the first time but later show it every 3 times
Got any ideas? :D
PS. I prefer staying basic and only use a for loop
Have a nice evening

Could you just check if the i is not zero when you assign the value of output.sum?
Something like the following:
let i = 0;
const inputBuffer = [];
const randomnumber = (min, max) => {
return Math.floor(Math.random() * (max - min + 1) + min);
}
for (let k = 0; k < 10; k++) {
console.log(convert(randomnumber(0, 1982)));
}
function convert(input) {
inputBuffer.push(input);
const output = {"current" : "0"};
if (i % 3 == 0) {
let sum = 0;
for (let ii = 0; ii < i; ii++) {
sum += inputBuffer[ii];
}
if (i !== 0) output.sum = sum; // HERE
}
i++;
output.current = input;
return JSON.stringify(output);
}

I found this out, yours is obviously shorter but here was my Idea :D
let i = 0;
const inputBuffer = [];
let db = false;
const randomnumber = (min, max) => {
return Math.floor(Math.random() * (max - min + 1) + min);
}
for (let k = 0; k < 10; k++) {
console.log(convert(randomnumber(0, 1982)));
}
function convert(input) {
inputBuffer.push(input);
const output = {"current" : "0"};
if (db && i % 3 == 0) {
let sum = 0;
for (let ii = 0; ii < i; ii++) {
sum += inputBuffer[ii];
}
output.sum = sum;
}
i++
db = true;
output.current = input;
return JSON.stringify(output);
}

Given a sequence of integers, return the sum of all the integers that have an even index, multiplied by the integer at the last index

This is my solution and it passes some of the tests, but not all of them. Can anyone help me and explain why? Thank you :)
function evenLast(numbers) {
let sum = 0;
let lastNum = numbers.pop();
let arr = numbers.filter(el => el % 2 === 0);
for(let i = 0; i < arr.length; i++) {
sum += (arr[i] * lastNum);
}
return sum;
}

You need to check the index, not the value
let arr = numbers.filter((_, i) => i % 2 === 0);
And you could multiply the sum at the last step.
for (let i = 0; i < arr.length; i++) {
sum += arr[i]);
}
return sum * lastNum;
A better approach takes only a single loop and sums the values by taking an increment of two.
function evenLast(numbers) {
let sum = 0;
for (let i = 0; i < numbers.length; i += 2) sum += numbers[i];
return sum * numbers[numbers.length - 1];
}

function evenLast(arr) {
var lastarr = arr.slice(arr.length-1)
//return lastarr;
let newarr = [];
for(i=0; i<arr.length; i++){
if(arr[i] % 2 === 0) {
newarr.push(arr[i]);
}
}
//return newarr;
var sum1 =0;
for(i=0; i<newarr.length; i++) {
var sum = newarr[0] * lastarr[0];
var sum1 = newarr[1] * lastarr[0];
//return sum;
var sum2 = sum1 + sum;
//i++;
}
return sum2;
}
console.log(evenLast([2, 3, 4, 5]))

How to program Pascal's Triangle in Javascript - confusion re Arrays

I'm having a little trouble with my attempt at this problem. Code Below:
function pasc(n){
var result = [[1]];
for (var row = 1; row < n; row++){
for (var col = 1; col <= row; col++){
result[row][col] = result[row - 1][col] + result[row - 1][col - 1];
}
}
return result;
}
pasc(10)
for (var i = 0; i < result.length; i++){
document.write(result[i]+"<br>");
}
It seems the problem hinges on assigning values to an array using an expression like myArray[1][1] = "foo"
I'm confused about this because I can do this: var myArray = []; myArray[4] = "foo" which seems to suggest that an element can be created at an arbitrary position in a 1 dimensional array, but not with 2 dimensions.
Any help with clearing up my misconceptions appreciated.

The Pascal's Triangle can be printed using recursion
Below is the code snippet that works recursively.
We have a recursive function pascalRecursive(n, a) that works up till the number of rows are printed. Each row is a element of the 2-D array ('a' in this case)
var numRows = 10,
triangle,
start,
stop;
// N is the no. of rows/tiers
// a is the 2-D array consisting of the row content
function pascalRecursive(n, a) {
if (n < 2) return a;
var prevRow = a[a.length-1];
var curRow = [1];
for (var i = 1; i < prevRow.length; i++) {
curRow[i] = prevRow[i] + prevRow[i-1];
}
curRow.push(1);
a.push(curRow);
return pascalRecursive(n-1, a); // Call the function recursively
}
var triangle = pascalRecursive(numRows, [[1]]);
for(var i = 0; i < triangle.length; i++)
console.log(triangle[i]+"\n");

JavaScript doesn't have two-dimensional arrays. What it does have is arrays that happen to contain other arrays. So, yes, you can assign a value to any arbitrary position in an array, and the array will magically make itself big enough, filling in any gaps with 'undefined'... but you can't assign a value to any position in a sub-array that you haven't explicitly created yet. You have to assign sub-arrays to the positions of the first array before you can assign values to the positions of the sub-arrays.
Replacing
for (var row = 1; row < n; row++){
for (var col = 1; col <= row; col++){
with
for (var row = 1; row < n; row++){
result[row] = [];
for (var col = 1; col <= row; col++){
should do it. Assuming all of your indexing logic is correct, anyway. You've got some problems there, too, since your initial array only contains a single value, so result[row][col] = result[row - 1][col] + result[row - 1][col - 1]; is accessing at least one cell that has never been defined.

Thanks Logan R. Kearsley. I have now solved it:
function pasc(n){
var result = [];
result[0] = [1];
result[1] = [1,1];
for (var row = 2; row < n; row++){
result[row] = [1];
for (var col = 1; col <= row -1; col++){
result[row][col] = result[row-1][col] + result[row-1][col-1];
result[row].push(1);
}
}
return result;
}
for (var i = 0; i < pasc(10).length; i++){
document.write(pasc(10)[i]+"<br>");
console.log(pasc(10)[i]+"<br>");
}

you can create Pascal's triangle using below code:
function pascal(n) {
var arr = [];
if (n == 1) {
arr[0] = [];
arr[0][0] = 1;
} else if (n == 2) {
arr[0] = [];
arr[0][0] = 1;
arr[1] = [];
arr[1][0] = 1;
arr[1][1] = 1;
} else if (n > 2) {
arr[0] = [];
arr[1] = [];
arr[0][0] = 1;
arr[1][0] = 1;
arr[1][1] = 1;
for (i = 2; i < n; i++) {
arr[i] = [];
arr[i][0] = 1;
for (j = 1; j < i; j++) {
arr[i][j] = arr[i - 1][j - 1] + arr[i - 1][j];
}
arr[i][j] = 1;
}
}
console.log(arr);
for (i = 0; i < arr.length; i++) {
console.log(arr[i].join(' '))
}
}
function pascal(n) {
var arr = [];
if (n == 1) {
arr[0] = [];
arr[0][0] = 1;
} else if (n == 2) {
arr[0] = [];
arr[0][0] = 1;
arr[1] = [];
arr[1][0] = 1;
arr[1][1] = 1;
} else if (n > 2) {
arr[0] = [];
arr[1] = [];
arr[0][0] = 1;
arr[1][0] = 1;
arr[1][1] = 1;
for (i = 2; i < n; i++) {
arr[i] = [];
arr[i][0] = 1;
for (j = 1; j < i; j++) {
arr[i][j] = arr[i - 1][j - 1] + arr[i - 1][j];
}
arr[i][j] = 1;
}
}
console.log(arr);
for (i = 0; i < arr.length; i++) {
console.log(arr[i].join(' '))
}
}
pascal(5)

This function will calculate Pascal's Triangle for "n" number of rows. It will create an object that holds "n" number of arrays, which are created as needed in the second/inner for loop.
function getPascalsTriangle(n) {
var arr = {};
for(var row = 0; row < n; row++) {
arr[row] = [];
for(var col = 0; col < row+1; col++) {
if(col === 0 || col === row) {
arr[row][col] = 1;
} else {
arr[row][col] = arr[row-1][col-1] + arr[row-1][col];
}
}
}
return arr;
}
console.log(getPascalsTriangle(5));

Floyd triangle
You can try the following code for a Floyd triangle
var prevNumber=1,i,depth=10;
for(i=0;i<depth;i++){
tempStr = "";j=0;
while(j<= i){
tempStr = tempStr + " " + prevNumber;
j++;
prevNumber++;
}
console.log(tempStr);
}

You can create arbitrary 2d arrays and store it in there and return the correct Pascal.
JavaScript does not have a special syntax for creating multidimensional arrays. A common workaround is to create an array of arrays in nested loops.
source
Here is my version of the solution
function pascal(input) {
var result = [[1], [1,1]];
if (input < 0) {
return [];
}
if (input === 0) {
return result[0];
}
for(var j = result.length-1; j < input; j++) {
var newArray = [];
var firstItem = result[j][0];
var lastItem = result[j][result[j].length -1];
newArray.push(firstItem);
for (var i =1; i <= j; i++) {
console.log(result[j][i-1], result[j][i]);
newArray.push(sum(result[j][i-1], result[j][i]));
}
newArray.push(lastItem);
result.push(newArray);
}
return result[input];
}
function sum(one, two) {
return one + two;
}

Here is the code i created for pascal triangle in javascript
'use strict'
let noOfCoinFlipped = 5
let probabiltyOfnoOfHead = 2
var dataStorer = [];
for(let i=0;i<=noOfCoinFlipped;i++){
dataStorer[i]=[];
for(let j=0;j<=i;j++){
if(i==0){
dataStorer[i][j] = 1;
}
else{
let param1 = (j==0)?0:dataStorer[i-1][j-1];
let param2 = dataStorer[i-1][j]?dataStorer[i-1][j]:0;
dataStorer[i][j] = param1+param2;
}
}
}
let totalPoints = dataStorer[noOfCoinFlipped].reduce((s,n)=>{return s+n;})
let successPoints = dataStorer[noOfCoinFlipped][probabiltyOfnoOfHead];
console.log(successPoints*100/totalPoints)
Here is the link as well
http://rextester.com/TZX59990

This is my solve:
function pascalTri(n){
let arr=[];
let c=0;
for(let i=1;i<=n;i++){
arr.push(1);
let len=arr.length;
if(i>1){
if(i>2){
for(let j=1;j<=(i-2);j++){
let idx=(len-(2*i)+j+2+c);
let val=arr[idx]+arr[idx+1];
arr.push(val);
}
c++;
}
arr.push(1);
}
}
return arr;
}
let pascalArr=pascalTri(7);
console.log(pascalArr);

here is the pattern for n = 3
#
##
###
here is js code to print this.
function staircase(n) {
for(var i=0 ; i<n ; i++) {
for(var j=n-1 ; j>i ; j--)
process.stdout.write(" ");
for(var k=0 ; k<=i; k++) {
process.stdout.write("#");
}
process.stdout.write("\n");
}
}

class PascalTriangle {
constructor(n) {
this.n = n;
}
factoriel(m) {
let result = 1;
if (m === 0) {
return 1;
}
while (m > 0) {
result *= m;
m--;
}
return result;
}
fill() {
let arr = [];
for (let i = 0; i < this.n; i++) {
arr.push([]);
}
for (let i = 0; i < arr.length; i++) {
for (let j = 0; j <= i; j++) {
arr[i].push(this.factoriel(i) / (this.factoriel(j) * this.factoriel(i - j)));
}
}
return arr;
}
}

var m = prompt("enter number:");
var arrMain = new Array();
for (var i = 0; i < m; i++) {
arrMain[i] = [];
}
for (var i = 0; i < m; i++) {
if (i == 0) {
arrMain[i] = [1];
} else if (i == 1) {
(arrMain[i]) = [1, 1];
} else {
for (var j = 0; j <= i; j++) {
if (j == 0 || j == arrMain[i - 1].length) {
arrMain[i][j] = 1;
} else {
arrMain[i][j] = arrMain[i - 1][j] + arrMain[i - 1][j - 1];
}
}
}
document.write(arrMain[i] + "<br>");
}

This is my take on this problem by gaining access to the previous row.
const generate = numRows => {
const triangle = [[1]]
for (let i = 1; i < numRows; i++) {
// Previous row
const previous = triangle[i - 1]
// Current row
const current = new Array(i + 1).fill(1)
// Populate the current row with the previous
// row's values
for (let j = 1; j < i; j++) {
current[j] = previous[j - 1] + previous[j]
}
// Add to triangle result
triangle.push(current)
}
return triangle
}