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Python – Find the difference of the sum of list elements that are missing from Matrix and vice versa

  • Difficulty Level : Easy
  • Last Updated : 18 Jul, 2021

Given a list and a Matrix, the task is to write a Python program that can find the difference of the sum of list elements that are missing from Matrix and vice versa.

A simpler explanation says, find and sum all elements found in Matrix but not in list. Next, find and sum all elements found in list which are not in matrix. Perform difference between sum values extracted.

Input : test_list = [[2, 4, 1], [8, 1, 2], [9, 1, 10], [4, 3, 2]], tar_list = [2, 3, 10, 7, 5, 4] 
Output : 8 
Explanation : 8 + 9 + 1 + 1 + 1 = 20 [ Elements in Matrix, not in list ]
7 + 5 = 12 [ Elements in list, not in Matrix ]
Difference = 12 – 20 = 8.
 

Input : test_list = [[2], [8], [9], [4]], tar_list = [2, 3, 10, 7, 5, 4] 
Output : 8 
Explanation : 8 + 9 = 17 [ Elements in Matrix, not in list ]
3 + 10 + 7 + 5 = 25 [ Elements in list, not in Matrix ]
Difference = 25 – 17 = 8.
 

Method 1 : Using loop and from_iterable()



In this, we get the list sum of elements present in the list and not the matrix and vice versa using a counter in loop and compute the difference. The from_iterable() is used to flatten matrix.

Example:

Python3




# Python3 code to demonstrate working of
# Missing elements difference from Matrix and List
# Using loop
from itertools import chain
  
# initializing list
test_list = [[2, 4, 1], [8, 1, 2], [9, 1, 10], [4, 3, 2]]
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing target list
tar_list = [2, 3, 10, 7, 5, 4]
  
# flattening Matrix
flat_mat = list(chain.from_iterable(test_list))
  
# getting sum of list elements not in Matrix
list_sum = 0
for ele in tar_list:
    if ele not in flat_mat:
        list_sum += ele
  
# getting sum of Matrix elements not in list
mat_sum = 0
for ele in flat_mat:
    if ele not in tar_list:
        mat_sum += ele
  
# computing difference
res = abs(mat_sum - list_sum)
  
# printing result
print("The computed count : " + str(res))

 Output:

The original list is : [[ 2, 4, 1], [8, 1, 2], [8, 1, 2], [9, 1, 10], [4, 3, 2]]

The computed count : 8

Method 2 : Using sum() and from_iterable()

In this, task of computing summation is done using sum(), rest all functionality is performed in same way as above method.



Example:

Python3




# Python3 code to demonstrate working of
# Missing elements difference from Matrix and List
# Using sum() + from_iterable()
from itertools import chain
  
# initializing list
test_list = [[2, 4, 1], [8, 1, 2], [9, 1, 10], [4, 3, 2]]
  
# printing original list
print("The original list is : " + str(test_list))
  
# initializing target list
tar_list = [2, 3, 10, 7, 5, 4]
  
# flattening Matrix
flat_mat = list(chain.from_iterable(test_list))
  
# getting sum of list elements not in Matrix
list_sum = sum([ele for ele in tar_list if ele not in flat_mat])
  
# getting sum of Matrix elements not in list
mat_sum = sum([ele for ele in flat_mat if ele not in tar_list])
  
# computing difference
res = abs(mat_sum - list_sum)
  
# printing result
print("The computed count : " + str(res))

Output:

The original list is : [[2, 4, 1], [8, 1, 2], [9, 1, 10], [4, 3, 2]]

The computed count : 8

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