Pedro Tome

#
# The Collatz Conjecture Buster (not)
# version 1.1 (added {Export as Excel feature} and {Choice Validity Tests})
# By Pedro Tome'
#
# This script needs the pyExcelerator module,
# available at http://sourceforge.net/projects/pyexcelerator/
#


# Setting variables:
while True: # Minimum number validity test
    try:
        min_num = int(raw_input("Minimum number: "))
        if min_num < 2:
            print "Error: must be a number equal or higher than 2!"
            continue
        else:
            break
    except ValueError:
        print "Error: must be a number equal or higher than 2!"
        continue


while True: # Maximum number validity test
    try:
        max_num = int(raw_input("Maximum number: "))
        if max_num < min_num:
            print "Error: must be equal or higher than the maximum number %i!" % (min_num)
            continue
        else:
            break
    except ValueError:
        print "Error: must be a number equal or higher than the maximum number %i!" % (min_num)
        continue


while True: # Screen printing choice validity test
    print_choice = raw_input("Print all numbers on the screen? (faster if you choose not to) [1 or 0] ") # Printing everything makes the process slower...
    if print_choice != "0" and print_choice != "1":
        print "Error: must be 0 or 1"
        continue
    else:
        print_choice = int(print_choice)
        break


while True: # Excel exporting choice validity test
    excel_choice = raw_input("Export as an Excel spreadsheet? [1 or 0] ")
    if excel_choice != "0" and excel_choice != "1":
        print "Error: must be 0 or 1"
        continue
    else:
        excel_choice = int(excel_choice)
        break


a = min_num
loop_num = 0
found_num = False
#

if excel_choice == 1:
    from pyExcelerator import *
    wb = Workbook()
    ws0 = wb.add_sheet("0")

    excel_filename = raw_input("Excel spreadsheet filename: ")
    ws0.write(0,0,"Number")
    ws0.write(0,1,"Steps")

    y = 1

    # The actual loop/calculator:
    if max_num - min_num >= 20000:
        print "Calculating..."
    else:
        pass

    while a <= max_num:
        b = a

        while b != 1:
            if b%2 == 0: # If b is even (b%2 = remainder of b/2)
                b = b/2
            else: # If b is odd
                b = 3*b+1
            loop_num += 1

        # Printing on the Excel spreadsheet
        ws0.write(y,0,a)
        ws0.write(y,1,loop_num)
        y += 1
        #

        if b < 1:
            print "Exception found! Number %i!" % (a) # This is obviously impossible... :(
            raw_input("Press ENTER to exit.") # Must use this so the program doesn't close immediately after finishing on Windowze CMD
            found_num = True
            break
        else:
            if print_choice == 1:
                print "%i - %i steps" %(a,loop_num)
            loop_num = 0 # loop_num must be reset so loop_num(a) doesn't add with loop_num(a+1)
            a += 1

    if found_num == False:
        print "Done calculating."
        print "\nExporting to Excel..."
        wb.save(excel_filename+".xls")
        print "Done."
        raw_input("\nPress ENTER to exit.") # Must use this so the program doesn't close immediately after finishing on Windowze CMD
    #

else:
    # The actual loop/calculator:
    if max_num - min_num >= 20000:
        print "Calculating..."
    else:
        pass

    while a <= max_num:
        b = a

        while b != 1:
            if b%2 == 0: # If b is even (b%2 = remainder of b/2)
                b = b/2
            else: # If b is odd
                b = 3*b+1
            loop_num += 1

        if b < 1:
            print "Exception found! Number %i!" % (a) # This is obviously impossible... :(
            raw_input("Press ENTER to exit.") # Must use this so the program doesn't close immediately after finishing on Windowze CMD
            found_num = True
            break
        else:
            if print_choice == 1:
                print "%i - %i steps" %(a,loop_num)
            loop_num = 0 # loop_num must be reset so loop_num(a) doesn't add with loop_num(a+1)
            a += 1

    if found_num == False:
        print "Done calculating."
        raw_input("\nPress ENTER to exit.") # Must use this so the program doesn't close immediately after finishing on Windowze CMD
    #