https://leetcode.com/problems/pascals-triangle-ii/submissions/

pascalsTriangleII.js

/**
 * @param {number} rowIndex
 * @return {number[]}
 */
var getRow = function(index) {
    if(index === 0) return [1];
    let [result, next] = [[1], []];
  
    for(let row=1; row<=index; row++){
        for(let j=0; j<=result.length; j++){
            const prev = result[j-1] || 0;
            const curr = result[j] || 0;
            next.push(prev + curr);
        }
        result = next;
        next = [];
    }
    
    return result;
};