index.js

/**
 * @param {number} lineNumber - zero based.
 * @return {number[]}
 */

const pascalTriangle = (lineNumber) => {
  const pascalTrianglePerLine = [];            //  Its like a multidimensional array (but really not, is just an array of arrays), saves line per line the pascal triangle to return later que specific line

  for (let i = 0; i <= lineNumber; i++) {
    let newLine = [];
    for (let j = 0; j <= i; j++) {
      if (j === 0 || j === i) {                                 //  The first and last time at the second cicle need have a 1 becaues thats the border of the triangle
        newLine.push(1);
      } else {
        newLine.push(
          pascalTrianglePerLine[i - 1][j - 1] + pascalTrianglePerLine[i - 1][j]   //  If is not the first line, need to take the top left and top right numbers and add them
        );
      }
    }
    pascalTrianglePerLine.push(newLine);
  }
  return pascalTrianglePerLine[lineNumber];
};

module.exports = pascalTriangle;