Finding the elements of nth row of Pascal's triangle in JavaScript

Pascal's triangle:

Pascal's triangle is a triangular array constructed by summing adjacent elements in preceding rows.

The first few elements of Pascals triangle are −

We are required to write a JavaScript function that takes in a positive number, say num as the only argument.

The function should return an array of all the elements that must be present in the pascal's triangle in the (num)th row.

For example −

If the input number is −

const num = 9;

Then the output should be −

const output = [1, 9, 36, 84, 126, 126, 84, 36, 9, 1];

Example

Following is the code −

const num = 9;
const pascalRow = (num) => {
   const res = []
   while (res.length <= num) {
      res.unshift(1);
      for(let i = 1; i < res.length - 1; i++) {
         res[i] += res[i + 1];
      };
   };
   return res
};
console.log(pascalRow(num));

Output

Following is the console output −

[
   1, 9, 36, 84, 126,
   126, 84, 36, 9, 1
]

AmitDiwan

Published on 22-Jan-2021 06:42:29

• Related Questions & Answers
• Program to find the nth row of Pascal's Triangle in Python
• Pascal's Triangle in C++
• Pascal's Triangle II in C++
• Java program to print Pascal's triangle
• Finding the sum of all numbers in the nth row of an increasing triangle using JavaScript
• Python Program to Print the Pascal's triangle for n number of rows given by the user
• C# Program to create Pascal’s Triangle
• Finding area of triangle in JavaScript using Heron’s formula
• Finding the nth digit of natural numbers JavaScript
• Finding nth element of the Padovan sequence using JavaScript
• Finding the nth element of the lucas number sequence in JavaScript
• Finding the nth power of array element present at nth index using JavaScript
• How to print integers in the form of Pascal triangle using C?
• Finding sum of every nth element of array in JavaScript
• Finding nth digit of natural numbers sequence in JavaScript