# Print all subset combinations of n element in given set of r element.


def combination_util(arr, n, r, index, data, i):
 """
 Current combination is ready to be printed, print it
 arr[] ---> Input Array
 data[] ---> Temporary array to store current combination
 start & end ---> Staring and Ending indexes in arr[]
 index ---> Current index in data[]
 r ---> Size of a combination to be printed
 """
 if index == r:
 for j in range(r):
 print(data[j], end=" ")
 print(" ")
 return
 # When no more elements are there to put in data[]
 if i >= n:
 return
 # current is included, put next at next location
 data[index] = arr[i]
 combination_util(arr, n, r, index + 1, data, i + 1)
 # current is excluded, replace it with
 # next (Note that i+1 is passed, but
 # index is not changed)
 combination_util(arr, n, r, index, data, i + 1)
 # The main function that prints all combinations
 # of size r in arr[] of size n. This function
 # mainly uses combinationUtil()


def print_combination(arr, n, r):
 # A temporary array to store all combination one by one
 data = [0] * r
 # Print all combination using temporary array 'data[]'
 combination_util(arr, n, r, 0, data, 0)


# Driver function to check for above function
arr = [10, 20, 30, 40, 50]
print_combination(arr, len(arr), 3)
# This code is contributed by Ambuj sahu