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?
这题和前面一题的区别在于不用返回所有解,只需要返回index对应行就行。做法和前面的一样定义一个currow 和prerow
class Solution: # @return a list of integers def getRow(self, rowIndex): rownum=rowIndex+1 currow=[1] if rownum==1: return currow if rownum>0: currow=[1] for index in range(rownum): prerow=currow currow=[1] for j in range(index-1): currow.append(prerow[j]+prerow[j+1]) currow.append(1) return currow
Pascal's triangle II Leetcode Python
时间: 2024-10-10 17:48:38