Coin change - python

Question

1. My denomination "5" is not showing up and how do you reverse the dict easily. i dont want extra 5 line of code.lol
2. Can you guys help me out with it?

3. the code is working so far.

4. here is my code with a test case

   def change(target, coins):
       result = dict()
       i= len(coins) -1
       while i> 0:
           coin = coins[i]
           numOfThisCoin= target // coin
           result[coin] = numOfThisCoin
           target -= coin * numOfThisCoin
           i-= 1
       return result
   
   print(change(185, (5, 10, 25, 100, 200)))
   

i am getting output

    {200: 0, 100: 1, 25: 3, 10: 1}

but want it like

    {5: 0, 10: 1, 25: 3, 100: 1, 200: 0}

Answer 1

Here is the corrected code for your problem:

from collections import OrderedDict

def change(target, coins):
    result = dict()
    i= len(coins) -1
    while i>= 0:
        coin = coins[i]
        numOfThisCoin= target // coin
        result[coin] = numOfThisCoin
        target -= coin * numOfThisCoin
        i-= 1
    res = OrderedDict(sorted(result.items()))
    return res

print(change(185, (5, 10, 25, 100, 200)))

If you (not only 25 you can access any coin denomination)

print(res[25])

Output will be

3

in this case. dict- it does not keep the elements in order. You have to use OrderedDict for sorting the elements in the order you want. For more info follow the below link:

http://docs.python.org/library/collections.html#collections.OrderedDict

Answer 2

def change(target, coins):
    result = dict()
    i= len(coins) -1
    while i>= 0:
        coin = coins[i]
        numOfThisCoin= target // coin
        result[coin] = numOfThisCoin
        target -= coin * numOfThisCoin
        i-= 1
    return dict(sorted(result.items()))

print(change(185, (5, 10, 25, 100, 200)))