Sum of All Matrix Entries

Problem

Sum every entry of a matrix A.

Return the total of all elements across all rows and columns. The empty matrix sums to 0.

Hint

Sum each row first, then sum the row totals.

case 1

in: [[[1,2],[3,4]]]

expected: 10

case 2

in: [[[1,-2,3],[-4,5,-6]]]

expected: -3

case 3

in: [[[7]]]

expected: 7

case 4

in: [[[0.5,1.5],[2.5,3.5]]]

expected: 8

case 5

in: [[]]

expected: 0

Starter codePython

def matrix_entry_sum(A):
    # Your code here
    pass

5 test cases · run your code against them in the editor