Have what problem, ask me this method basically no problem when n is small, several big up then there is something wrong with the
1. Title:

2. Solution:

 
The class Solution: 
Def numWays (self, n: int) - & gt; Int: 
Steps=int (n/2) 
Nums=0 
For step in range (+ 1) steps: 
Tstep=n - step * 2 + step 
Nums +=self. C (tstep, step) 
Return int (nums % 1000000007) 

Def c (self, n, m) : 
"" "
O combinations of 
"" "
Return int (math) factorial (n)/(math) factorial (m) * math.h factorial (n, m))) % 1000000007 

CodePudding user response:

Not (n - 1) + (n - 2) number? Why so complicated

CodePudding user response:

It's not complicated, is not a problem of permutation and combination

CodePudding user response:

Is this meaning?

 def f (n) : 
L=[0, 1] 
For I in range (1, n + 1) : 
L=[l [1], the sum (l)] 
Return the l 
Print (f (7) [1])