README.md

119. Pascal's Triangle II

Given a non-negative index k where k ≤ 33, return the k^th index row of the Pascal's triangle.

Note that the row index starts from 0.

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

Example 1:

Input: 3
Output: [1,3,3,1]

Follow up:

Could you optimize your algorithm to use only O(k) extra space?

Solutions (Python)

1. Solution

class Solution:
    def getRow(self, rowIndex: int) -> List[int]:
        row = [1] * (rowIndex + 1)
        for i in range(2, rowIndex + 1):
            prenum = 1
            for j in range(1, i):
                row[j], prenum = row[j] + prenum, row[j]
            row[j + 1] = 1
        return row