01_diagonal_differences.py

# v2
matrix = [list(map(int, input().split())) for _ in range(int(input()))]
diagonal1 = [(matrix[i][i]) for i in range(len(matrix))]
diagonal2 = [(matrix[i][(len(matrix)-i-1)]) for i in range(len(matrix))]
print(abs(sum(diagonal1) - sum(diagonal2)))





# v1 - faster
matrix = [list(map(int, input().split())) for _ in range(int(input()))]
diagonal1 = [(matrix[i][i]) for i in range(len(matrix))]
diagonal2 = [matrix[i[0]][i[1]] for i in tuple(
    zip([h for h in range(len(matrix))], [v for v in range(len(matrix) - 1, -1, -1)]))]
print(abs(sum(diagonal1) - sum(diagonal2)))





# REGULAR SHOW
n = int(input())
matrix = list()
for _ in range(n):
    matrix.append(
        list(map(int, input().split()))
    )
diagonal_started_top_left = list()
for i in range(len(matrix)):
    diagonal_started_top_left.append(
        matrix[i][i]
  )
diagonal_started_top_right = list()
list_1 = list()
for h in range(len(matrix)):
    list_1.append(h)
list_2 = []
for v in range(len(matrix) - 1, -1, -1):
    list_2.append(v)
for i in tuple(zip(list_1, list_2)):
    vertical, horizontal = i[0], i[1]
    diagonal_started_top_right.append(
        matrix[vertical][horizontal]
    )
summed_top_left, summed_top_right = sum(diagonal_started_top_left), sum(diagonal_started_top_right)
result = summed_top_left - summed_top_right
print(abs(result))