题解 | #杨辉三角(一)#

class Solution:
    def generate(self , num: int) -> List[List[int]]:
        # write code here
        triangle=[]
        triangle.append([1])
        for i in range(num-1):
            triangle.append([x+y for x,y in zip([0]+triangle[i],triangle[i]+[0])])
        return triangle

杨辉三角第n行等于第n-1行分别首尾补0，然后按位相加，如下：

[1,1]=[0,1]+[1,0]

[1,2,1]=[0,1,1]+[1,1,0]

[1,3,3,1]=[0,1,2,1]+[1,2,1,0]

…………