用Python写一个贪婪算法

来解决一个背包问题，你怎么做？

可以使用以下代码实现：

def knapsack_greedy(capacity, weights, values):
n = len(weights)
ratios = [v / w for v, w in zip(values, weights)]
ratios_sorted_idx = sorted(range(n), key=lambda i: ratios[i], reverse=True)

value = 0
weight = 0
knapsack = []

for i in ratios_sorted_idx:
if weight + weights[i] <= capacity:
knapsack.append(i)
weight += weights[i]
value += values[i]

return knapsack, value