input: Write a function that takes an array of integers and computes the sum of the squares of all the numbers in the array. If the array is empty, return 0.
  assert sum_squares([2, 3, 4])==29
  assert sum_squares([1, 2, 3, 4, 5])==55
  assert sum_squares([])==0
  assert sum_squares([-1, -2, -3])==14
  assert sum_squares([0])==0
output: def sum_squares(arr):
      return sum(x**2 for x in arr)