Combinations (Leetcode 77)

Hint: Similar to subsets problem (Use Choose or don't choose method)

Problem Link: https://leetcode.com/problems/combinations/

class Solution:
    def combine(self, n: int, k: int) -> List[List[int]]:
        
        ans=[]
        def recursion(i,n,tempAns,k):
            
            # If the number of remaining spaces for the combination
            # is greater than available integers, we cannot get
            # a combination of k size.
            if(k-len(tempAns)>n-i+1):
                return
            
            
            # If we have reached size k for a combination,
            # store the combination in ans and return from there.
            if(len(tempAns)==k):
                ans.append(tempAns)
                return
                
            temp=tempAns[:]
            temp.append(i)
            recursion(i+1,n,tempAns,k)
            recursion(i+1,n,temp,k)
        
        
        recursion(1,n,[],k)
        return ans