On Jan 11, 9:46 am, Gary Herron <[EMAIL PROTECTED]> wrote: > Tom_chicollegeboy wrote: > > here is what I have to do: > > > This question involves a game with teddy bears. The game starts when I > > give you some bears. You then start giving me back some bears, but you > > must follow these rules (where n is the number of bears that you > > have): > > This sounds very much like a homework assignment, and so should probably > not be answered here. (Neither should it have been asked here.) If, > in your attempt to write this program, you have some questions about > Python, then I encourage to ask those questions here. > > Gary Herron > > > If n is even, then you may give back exactly n/2 bears. (Hint: To test > > whether n is even, use the expression ((n % 2) == 0).) > > If n is divisible by 3 or 4, then you may multiply the last two digits > > of n and give back this many bears. (By the way, the last digit of n > > is n%10, and the next-to-last digit is (n%100)/10; this rule may not > > be used if either of the last two digits is 0.) > > > If n is divisible by 5, then you may give back exactly 42 bears. > > The goal of the game for you is to end up with EXACTLY 42 bears. > > > For example, suppose that you start with 250 bears. Then you could > > make these moves: > > > Start with 250 bears. > > Since 250 is divisible by 5, you may return 42 of the bears, leaving > > you with 208 bears. > > Since 208 is even, you may return half of the bears, leaving you with > > 104 bears. > > Since 104 is even, you may return half of the bears, leaving you with > > 52 bears. > > Since 52 is divisible by 4, you may multiply the last two digits > > (resulting in 10) and return these 10 bears. This leaves you with 42 > > bears. > > You have reached the goal! > > Now, you are to write a program that, if I give you n bears, returns > > true if it is at all possible for you to win the game. Your program > > must use recursion to check all possible ways in which you can apply > > the rules. > > > Usage: > > >>>> bears(42) > > > True > > >>>> bears(250) > > > True > > >>>> bears(50) > > > False > > >>>> bears(84) > > > True > > >>>> bears(41) > > > False > > > As you see my program must use recursion. > > > I came up with this idea but I am not sure if its right or are there > > any minor errors that I can easily fix: > > > def bears (n): > > if n==42: > > return True > > if n%5==0: > > bears(n-42) > > if n%2==0: > > bears(n/2) > > if n%3==0 or n%4==0: > > one = (n%10) > > two = ((n%100)/10) > > if one!=0 and two!=0: > > bears(n-(one*two)) > > return False > > > If a game hits 42 it should return True, otherwise False. If program > > never hits 42 and return True, then it returns False. I figured out > > base case, but I still get False when I enter bears(250). Any help > > would be very appreciated!
Note that for ; if one!=0 and two!=0: you can use if one and two: which is my pythonic. Also in your example with 52, shouldn't it divide by even first? Obviously this must not happen, thus maybe you should run a check that when you are returning a new value it does not go below 42? Frankly this looks like a terrible way to use recursion. -- http://mail.python.org/mailman/listinfo/python-list
