杨辉三角定义如下:
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
把每一行看做一个list,试写一个generator,不断输出下一行的list:
# 期待输出: # [1] # [1, 1] # [1, 2, 1] # [1, 3, 3, 1] # [1, 4, 6, 4, 1] # [1, 5, 10, 10, 5, 1] # [1, 6, 15, 20, 15, 6, 1] # [1, 7, 21, 35, 35, 21, 7, 1] # [1, 8, 28, 56, 70, 56, 28, 8, 1] # [1, 9, 36, 84, 126, 126, 84, 36, 9, 1]
def triangles():
L=[1]
yield L
while True:
L=[1]+[L[x]+L[x+1] for x in range(len(L)-1)]+[1]
yield L
n=0
for L in triangles():
print(L)
n=n+1
if n==10:
break