m*****n
发帖数: 74 | 1 Bunny stands at the bottom of a 10-step stair. She can jump 1 step or 2
steps upwards each turn until she reaches the top. How many different routes
can she take to reach the highest step? |
m*****n
发帖数: 74 | 2 To be clearer: she needs to exactly reach the 10th step, that's to say she
can't take a 2-step jump once she is at the 9th step
routes
【在 m*****n 的大作中提到】
: Bunny stands at the bottom of a 10-step stair. She can jump 1 step or 2
: steps upwards each turn until she reaches the top. How many different routes
: can she take to reach the highest step?
|
m*********g
发帖数: 11102 | 3 C(5,0)+C(6,2)+C(7,4)+C(8,6)+C(9,8)+C(10,10) = 89 ?
【在 m*****n 的大作中提到】
: To be clearer: she needs to exactly reach the 10th step, that's to say she
: can't take a 2-step jump once she is at the 9th step
:
: routes
|
f*****e
发帖数: 148 | |
m*****n
发帖数: 74 | 5 bingo!
【在 f*****e 的大作中提到】
: 89
|
m*****n
发帖数: 74 | 6 there is a better way to do it
【在 m*********g 的大作中提到】
: C(5,0)+C(6,2)+C(7,4)+C(8,6)+C(9,8)+C(10,10) = 89 ?
|
a******g
发帖数: 88 | 7 Fibonacci? :)
【在 m*****n 的大作中提到】
: bingo!
|
m*****n
发帖数: 74 | 8 on target!
【在 a******g 的大作中提到】
: Fibonacci? :)
|
o*******n
发帖数: 6500 | 9 f(n)=f(n-1)+f(n-2)
where f(1)=1, f(2)=2
f(10)=89
routes
【在 m*****n 的大作中提到】
: Bunny stands at the bottom of a 10-step stair. She can jump 1 step or 2
: steps upwards each turn until she reaches the top. How many different routes
: can she take to reach the highest step?
|
m*****n
发帖数: 74 | 10 you got it, fibonacci numbers
【在 o*******n 的大作中提到】
: f(n)=f(n-1)+f(n-2)
: where f(1)=1, f(2)=2
: f(10)=89
:
: routes
|
