[Algorithm] 118. Pascal's Triangle

Given a non-negative integer numRows, generate the first numRows of Pascal's triangle.

In Pascal's triangle, each number is the sum of the two numbers directly above it.

Example:

Input: 5
Output:
[
     [1],
    [1,1],
   [1,2,1],
  [1,3,3,1],
 [1,4,6,4,1]
]

/**
 * @param {number} numRows
 * @return {number[][]}
 */
var generate = function(numRows) {

    if (numRows === ) {
        return [];
    }

    let result = [];

    for (let i = ; i < numRows; i++) {
        let row = [];
        result.push(row);
        for (let j = ; j < i + ; j++) {
            if (j ===  || j === i) {
                row.push();
            } else {
                const temp = result[i-][j-] + result[i-][j];
                row.push(temp);
            }
        }
        result[i] = row;
    }

    return result;
};