1237

1237

# 组合
def order(start, tmp0=[]):
    for i in range(start, len(num)):
        tmp0.append(num[i])
        order(i+1, tmp0)
        if len(tmp0) == 3:
            queue.append(tmp0.copy())
        del tmp0[len(tmp0)-1]


# 排列
def permutations(arr, position, end):

    if position == end:
        print("{} {} {}".format(arr[0], arr[1], arr[2]))
    else:
        for index in range(position, end):
            arr[index], arr[position] = arr[position], arr[index]
            permutations(arr, position+1, end)
            arr[index], arr[position] = arr[position], arr[index]


num = list(map(int, input().split()))
queue = list()
order(0)
for i in queue:
    permutations(i, 0, len(i))

很明显OJ上有大佬写得更简单，我这个弟弟代码仅供参考。