LeetCode#118 Pascal's Triangle
Problem Definition:
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] ]
Solution: 关于杨辉三角
1 def generate(numRows): 2 pt=[] 3 for rn in range(numRows): 4 row=[0]*(rn+1) 5 row[0],row[rn]=1,1 6 for cl in range(1,rn): 7 p1=pt[rn-1][cl-1] 8 p2=pt[rn-1][cl] 9 row[cl]=p1+p2 10 pt+=[row] 11 return pt