Problem
Given a non-negative integer numRows, generate the first numRows of Pascal's triangle.
Example:
Input: 5
Output:
[
[1],
[1,1],
[1,2,1],
[1,3,3,1],
[1,4,6,4,1]
]
Solution
class Solution:
def generate(self, numRows: int) -> List[List[int]]:
ans = []
for i in range(1, numRows+1):
level = [1] * i
if ans:
for j in range(1, i-1):
level[j] = ans[-1][j-1] + ans[-1][j]
ans.append(level)
return ans