[leetcode]Pascal's Triangle II @ Python
原题地址:https://oj.leetcode.com/problems/pascals-triangle-ii/
题意:
Given an index k, return the kth row of the Pascal's triangle.
For example, given k = 3,
Return [1,3,3,1].
Note:
Could you optimize your algorithm to use only O(k) extra space?
解题思路:思路同上一道题。
class Solution:
# @return a list of integers
def getRow(self, rowIndex):
if rowIndex == 0: return [1]
if rowIndex == 1: return [1, 1]
list = [[] for i in range(rowIndex+1)]
list[0] = [1]
list[1] = [1, 1]
for i in range(2, rowIndex+1):
list[i] = [1 for j in range(i + 1)]
for j in range(1, i):
list[i][j] = list[i - 1][j - 1] + list[i - 1][j]
return list[rowIndex]
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