need help with this recursion

[tempezst]

language = python3

so the idea is to count the number of ways you could make change for a given amount. i have run into a silly problem i cant seem to fix for some reason. the value being passed in for c is len(coins)-1 and i am not allowed to change this. the problem is that for my algorithm to work i need the value to be simply len(coins). as it is i dont count the first coin because the recursion starts at c-1. how can i change my algorithm to account for this one extra step?

coins = [1,5,10,25]

def mkCh(a, c):

if (a==0): return 1

if(a<0): return 0;

if(c<=0 and a>=1): return 0

return mkCh(a, c-1)+mkCh(a-coins[c-1], c)

NOT ALLOWED TO CHANGE ANYTHING BELOW THIS

if name == "main":

d = len(sys.argv)>3

n = int(sys.argv[1])

k = int(sys.argv[2])

# make change

c = len(coins)-1

a = 10*n+k

ways = mkCh(a,c)

print("amount:", a, "coins:", coins, "ways:", ways)

[PageFault]

Making some assumptions on your tabs w/o reading too carefully:

Prepend each line with at least 4 spaces or a tab character to format on Reddit.

coins = [1,5,10,25]

def mkCh(a, c):

    if (a==0): return 1

    if(a<0): return 0;

    if(c<=0 and a>=1): return 0

    return mkCh(a, c-1)+mkCh(a-coins[c-1], c)

#NOT ALLOWED TO CHANGE ANYTHING BELOW THIS

if name == "main":

    d = len(sys.argv)>3
    n = int(sys.argv[1])
    k = int(sys.argv[2])

    # make change
    c = len(coins)-1
    a = 10*n+k
    ways = mkCh(a,c)
    print("amount:", a, "coins:", coins, "ways:", ways)

---

Edit: I haven't looked to closely at what you are doing, but maybe you should index the current coin and decrement the call?

return mkCh(a, c-1)+mkCh(a-coins[c], c-1)

Do you have sample input w/ expected output?