I think my python code works well for the problem (mentioned in the

subject) and it prints out all the possible solutions. But your compiler

says it doesn’t work. In the question, you asked for all the solutions.

But, I tried one of the successful codes (from your site) in c++14, which

shows only one possible solution, which does not fulfill the requirement.

Would you please check whether my code fails to provide the required

solutions? My code is provided below:

# -*- coding: utf-8 -*-

```
"""
https://www.codechef.com/problems/OPTSET
Optimal Xor Set
@author: shahriar.forhad.eee
"""
import itertools
import numpy as np
from operator import ixor as ix
from functools import reduce
def subsets(s, n):
return list(itertools.combinations(s, n))
t=int (input())
for tt in range(t):
n,k=map(int, (input().split()))
n=set(range(n+1))
n.remove(0)
sub_n=subsets(n, k)
r=[]
for j in range(len(sub_n)):
sub_n_=subsets(sub_n[j], 1)
sub_n_=np.array(sub_n_)
r.append(reduce(ix, sub_n_)) # res = reduce(lambda x, y: x ^ y, sub_n_)
r_max=max(r)
j=0
r_max_index=[]
for i in r:
if i==r_max:
r_max_index.append(j)
j=j+1
res=[]
for i in r_max_index:
res.append(sub_n[i])
for i in range(len(res)):
print(*res[i],sep=' ')
```