Week3-Loops.py

x = 0
while x < 5:
    print ("Current value of X is: " + str(x))
    x = x+1
print ("Final value of x: " + str(x))

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def attempts(n):
    x = 1
    while x <= n:
        print ("Attempt" + str(x))
        x += 1
    print ("Done")


attempts(5)

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x = 1
sum = 0
while x < 10:
    sum += x
    x += 1

print (sum)

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def count_down(start_number):
  current = start_number
  while (current > 0):
    print(current)
    current -= 1
  print("Zero!")


count_down(3)
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#Fill in the blanks to make the print_prime_factors function print all the prime factors of a number.
# A prime factor is a number that is prime and divides another without a remainder.

def print_prime_factors(number):
  # Start with two, which is the first prime
  factor = 2
  # Keep going until the factor is larger than the number
  while factor <= number:
    # Check if factor is a divisor of number
    if number % factor == 0:
      # If it is, print it and divide the original number
      print(factor)
      number = number / factor
    else:
      # If it's not, increment the factor by one
      factor += 1
  return "Done"

print_prime_factors(100)
# Should print 2,2,5,5
# DO NOT DELETE THIS COMMENT

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## The following code can lead to an infinite loop. Fix the code so that it can finish successfully for all numbers
def is_power_of_two(n):
    # Check if the number can be divided by two without a remainder
    while n != 0 and n % 2 == 0:
        n = n / 2
    # If after dividing by two the number is 1, it's a power of two
    if n == 1:
        return True
    return False


print(is_power_of_two(0))  # Should be False
print(is_power_of_two(1))  # Should be True
print(is_power_of_two(8))  # Should be True
print(is_power_of_two(9))  # Should be False

def sum_divisors(n):
  sum = 0
  x = 1
  while x < n:
        if n % x == 0:
            sum = sum + x
        x = x+1
  # Return the sum of all divisors of n, not including n
  return sum

#print(sum_divisors(0))
# 0
#print(sum_divisors(3)) # Should sum of 1
# 1
print(sum_divisors(36)) # Should sum of 1+2+3+4+6+9+12+18
# 55
#print(sum_divisors(102)) # Should be sum of 2+3+6+17+34+51
# 114