杨辉三角 python实现
题目
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
把每一行看作一个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]
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
把每一行看作一个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]
贴代码
- # -*- coding: utf-8 -*-
- def triangles():
- N=[1]
- while True:
- yield N #generator函数与普通函数的差别:在执行过程中,遇到yield就中断,下次又继续执行
- N.append(0)
- N=[N[i-1] + N[i] for i in range(len(N))] #写法
- if __name__ == '__main__':
- n=0
- for t in triangles():
- print(t)
- n=n+1
- if n == 10:
- break
result: