⚠️ 换成 4/3/1 呢

面值换成 4、3、1，要找 6。运行同样的程序：

def greedy(cs, t):
    n = 0
    for c in cs:
        while t >= c:
            t -= c
            n += 1
    return n

def best(cs, t):
    INF = 10 ** 9
    dp = [0] + [INF] * t
    for a in range(1, t + 1):
        for c in cs:
            if c <= a and dp[a - c] + 1 < dp[a]:
                dp[a] = dp[a - c] + 1
    return dp[t]

print(str(greedy([4, 3, 1], 6)) + "/" + str(best([4, 3, 1], 6)))