Pascal's Triangle

Given an integer numRows, return the first numRows of Pascal's triangle.

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

Example 1:

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

Example 2:

Input: numRows = 1
Output: [[1]]

Constraints:

• 1 <= numRows <= 30

SOLUTION:

class Solution:
    def generate(self, numRows: int) -> List[List[int]]:
        tri = []
        curr = [1]
        n = 1
        for i in range(numRows):
            tri.append(curr)
            curr = [0] + curr
            n += 1
            for i in range(n - 1):
                curr[i] = curr[i] + curr[i + 1]
        return tri