Hands-On Probability and Statistics 2: Advanced Techniques and Applications

Hands On: Probability and Statistics -2

Combinations and Permutations
Given an array, you should find the number of combinations and permutations when taken 2
elements at a time without a replacement that can be formed from the array of elements.
Function Description
Function Name: comb_perm()
1. Input:
arr - Numpy array
2. Output:
no_of_comb,no_of_perm : Integer

Sample Input For Custom Testing
4
A
B
C
D
Sample Output
(6, 12)
Explanation
No.of Combinations - 6
No. of Permutations - 12

Solution

from itertools import combinations
from itertools import permutations 
import numpy as np
import math

def comb_perm(arr):
    #Write your code here
    '''
    Input: arr : numpy array    
    Return : no_of_comb,no_of_perm : Integer
    
    
    '''
     
    n = len(arr)
    no_of_comb = len(list(combinations(arr, 2)))
    no_of_perm = math.factorial(n) // math.factorial(n-2)
    return no_of_comb,no_of_perm

if __name__=='__main__':
    array1=[]
    n=int(input())
    for i in range(n):
        array1.append(input())
    narray1=np.array(array1)
    print(comb_perm(narray1))