Day2-LeetCode 118. Pascal's Triangle

Problem: 118. Pascal's Triangle（Easy)

Pascal's Triangle:

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

思路:

row的次序与其所含number数量相同，先设定好first row，新的row由上列之两元素得到
因头尾皆为一，所以不计算头尾，直接判断後给值

My solution:

class Solution:
    def generate(self, numRows: int) -> List[List[int]]:
        triangle = [[1]]
        ans = []
        for i in range(1,numRows):
            for j in range(i+1):
                if j==0 or j==i:
                    ans.append(1)
                else:
                    ans.append(triangle[i-1][j-1]+ triangle[i-1][j])

            triangle.append(ans)
            ans = []

        return triangle

Result:

]

这题不难！
所以金拍谢，今日没有拿出厉害的哈哈哈

那明天挑战Medium吗？
要吗要吗