Pascal's Triangle · LeetCode Site Generator

Description

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]
]

Solution(javascript)

const generate = (numRows) => {
  const result = []
  for (let i = 0; i < numRows; i++) {
    const current = []
    for (let j = 0; j <= i; j++) {
      if (result[i - 1] && result[i - 1][j] && result[i - 1][j - 1]) {
        current.push(result[i - 1][j] + result[i - 1][j - 1])
      } else {
        current.push(1)
      }
    }
    result.push(current)
  }
  return result
}