标签：style blog http color os ar for div sp
Given numRows, generate the first numRows of Pascal‘s triangle.
For example, given numRows = 5,
Return
[
[1],
[1,1],
[1,2,1],
[1,3,3,1],
[1,4,6,4,1]
]
https://oj.leetcode.com/problems/pascals-triangle/
杨辉三角，先把两遍的值设为1，然后算中间的就是上一层的两个数相加，算当前层的时候，上一层下标一定是从0开始一直加到最后一个。
Python代码
class PascalsTriangle: def generate(self, numRows): res = [] for i in range(1, numRows+1): tem = [0 for x in range(i)] if i == 1: tem[0] = 1 # print(tem[0]) res.append(tem) else: pos = 0 for j in range(1, i+1): if j == 1: tem[0] = 1 elif j == i: tem[j - 1] = 1 else: tem[j-1] = res[i-2][pos] + res[i-2][pos+1] pos += 1 res.append(tem) return res p = PascalsTriangle() p.generate(5)
标签：style blog http color os ar for div sp
原文地址：http://www.cnblogs.com/aboutblank/p/3990943.html
