k=int(input())
a=[]
a.append(0)
a.append(1)
a.append(1)
a.append(2)
a.append(2)
s=0
for j in range(5,k+1):
 if j%2==1:
     for i in range(1,j//2+1):
         s+=a[i]
     a.append(s)

 else:
     for i in range(1,j//2):
         s+=a[i]
     s=s+a[j//2]-1
     a.append(s)
 s=0
print(a)

You are printing a, print(a).  A is a LIST.

FUUUCK, thanks, its so stupid error(

but code still not works, starting with the second test, and in example program gives WA, but I check code at least 3 times, I cant find errors((

I don't understand how does your algorithm work.  My AC - program is calculating values sequentially  for different ladders.  Time complexity is O(N*N*N).  So,  it is basically two dimensional dynamic programming.

And your algorithm has time complexity just O(N*N). It is not surprising that I can't understand it without explanation.  It is extremely optimized solution,  with heavy math behind.

Edited by author 23.06.2017 23:28

you don't need heavy math you can in O(n^2) time and O(n^2) space i don't know how u got O(n^3)
cin >> n;
    for(int i = 0; i < n; i++)
        dp[i][0] = 1;
    for(int i = 1; i < n; i++)
        for(int j = 1; j <= n; j++)
        {
            dp[i][j] = dp[i - 1][j];
            if(j >= i)
                dp[i][j] += dp[i - 1][j - i];
        }
    cout << dp[n - 1][n];

Edited by author 11.08.2017 05:18

Edited by author 11.08.2017 05:19

When I was solving it
I thought
There is a staircase consists of X cubes and it's height is Y
Then just add some new stair with height Z
Z is strictly greater than Y
Get new staircase with X+Z cubes and height Z

But also I know
There is a solution based on generating functions
I can't understand generating functions theory
So I have AC on task but don't understand generating functions and that guy didn't had AC at the moment
So probably generating functions are hard for him just like they are hard for me
That is why I have called generating functions "heavy math"

tell me more, do you know a good article for this?