Question

Write a Python function called sumNxN with three parameters. The first parameter is a nested list (matrix) representing a matrix of size N x N. The second parameter is the integer N, and the third is a list of N zeros.

Modify the list of zeros so that each entry is the sum of the corresponding column. There is no return.

Note: You may assume the sizes provided are all correct.

Answer 1

Solution:

The code is written in python3.

Code of the function sumNxN:

def sumNxN(matrix,N,L):
    for i in range(0,N):
        sum = 0
        for j in range(0,N):
            #Sum of a column
            sum += matrix[j][i]
        L[i] = sum

Code with implementation:

def sumNxN(matrix,N,L):
    for i in range(0,N):
        sum = 0
        for j in range(0,N):
            #Sum of a column
            sum += matrix[j][i]
        L[i] = sum

#for testing
matrix=[[1,2,3,4],
        [0,2,3,4],
        [4,3,2,1],
        [3,3,3,3]]
N=4
L=[0,0,0,0]

sumNxN(matrix,N,L)
print(L)

Screenshot of Code and output :