1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
|
# ###
# Coin sums
# Problem 31
#
# In England the currency is made up of pound, £, and pence, p, and there are eight coins in general circulation:
# 1p, 2p, 5p, 10p, 20p, 50p, £1 (100p) and £2 (200p).
# It is possible to make £2 in the following way:
# 1×£1 + 1×50p + 2×20p + 1×5p + 1×2p + 3×1p
# How many different ways can £2 be made using any number of coins?
# ###
coins = [200, 100, 50, 20, 10, 5, 2, 1]
solutions = []
def backtrack(n, sol):
if sum(sol) > n:
return
if n == 0:
solutions.append(sol)
return
while next_sol(n, sol):
backtrack(n, sol)
def next_(n, sol):
backtrack(10, [])
|
