118.pascals-triangle.py

from lc import *

class Solution:
    def generate(self, numRows) -> List[List[int]]:
        pascal = [[1]*(i+1) for i in range(numRows)]
        for i in range(numRows):
            for j in range(1,i):
                pascal[i][j] = pascal[i-1][j-1] + pascal[i-1][j]
        return pascal

class Solution:
    def generate(self, numRows) -> List[List[int]]:
            res = [[1]]
            for i in range(1, numRows):
                res += [list(map(lambda x, y: x+y, res[-1] + [0], [0] + res[-1]))]
            return res[:numRows]

class Solution:
    def generate(self, numRows) -> List[List[int]]:
        return reduce(lambda a,_:a+[list(map(lambda x,y:x+y,a[-1]+[0],[0]+a[-1]))],range(1,numRows),[[1]])[:numRows]

class Solution:
    def generate(self, n: int) -> List[List[int]]:
        return[*map(lambda i,f=factorial:[*map(lambda x:f(i)//f(x)//f(i-x),range(i+1))],range(n))]

class Solution:
    def generate(self, n: int) -> List[List[int]]:
        r,f=range,factorial;return[[f(i)//f(x)//f(i-x)for x in r(i+1)]for i in r(n)]

class Solution:
    def generate(self, n: int) -> List[List[int]]:
        r=range;return[[comb(i,x)for x in r(i+1)]for i in r(n)]

class Solution:
    def generate(self, n: int) -> List[List[int]]:
        return[[comb(i,x)for x in range(i+1)]for i in range(n)]

test('''
118. Pascal's Triangle
Easy

8267

275

Add to List

Share
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
''')