input: Write a function to check if all numbers from 1 to a given number are present in an array.
  assert find_all([1, 3, 5, 2], 5) == True
  assert find_all([1, 2, 3, 4], 4) == True
  assert find_all([1, 2, 4, 5], 5) == False
  assert find_all([1, 2, 3], 3) == True
output: def find_all(arr, n):
      return all(i in arr for i in range(1, n + 1))