import time
import cProfile
class Timer:
# on Windows this is more precise than 'time.time'.
function = time.clock
# is providing a start time
@staticmethod
def value():
return Timer.function()
# calculating delta between current time and start time.
@staticmethod
def delta(start):
return Timer.function() - start
# background information: http://en.wikipedia.org/wiki/Power_of_two
class PowerOfTwo:
# main calculation
@staticmethod
def calculateDigits(digits, n, f):
maxk = len(digits)-1
while n > 0:
rest = 0
k = 0
while k <= maxk:
digits[k] = digits[k] * f + rest
rest = digits[k] // 10
digits[k] %= 10
k += 1
if rest > 0:
digits.append(rest)
maxk += 1
n -= 1
# calculating the power of two
@staticmethod
def calculate(n):
digits = [1]
# little performance improvement
for k in [3, 2]:
if n > 2**k:
PowerOfTwo.calculateDigits(digits, n // k, 2**k)
n %= k
if n > 0:
PowerOfTwo.calculateDigits(digits, n, 2)
digits.reverse()
return digits
@staticmethod
def dump(digits, digitsPerRow = 50):
count = 0
text = ""
for digit in digits:
if count % digitsPerRow == 0:
text += "\n"
text += "%d" % (digit)
count += 1
print(text)
def main():
n = 4000
start = Timer.value()
digits = PowerOfTwo.calculate(n)
print("2^%d:" % (n))
print("...%d digits calculated" % (len(digits)))
print("...took %f seconds" % (Timer.delta(start)))
PowerOfTwo.dump(digits)
if __name__ == "__main__":
main()
#cProfile.run("main()")
