# a524 手機之謎 - Python 參考解答
撰寫人：Gandolfreddy

## 題目來源
* [a524: 手機之謎](https://zerojudge.tw/ShowProblem?problemid=a524)

## 參考程式碼解答
* 遞迴解法

while True:
    try:
        def permutate(nums, i, n):
            if i == n:
                perms.append(''.join(nums))
            else:
                for j in range(i, n):
                    nums[i], nums[j] = nums[j], nums[i]
                    permutate(nums, i+1, n)
                    nums[i], nums[j] = nums[j], nums[i]
        
        
        # input
        n = int(input())

        # process
        nums = list(map(str, range(1, n+1)))
        perms = []
        permutate(nums, 0, n)
        perms.sort(reverse=True)

        # output
        for perm in perms:
            print(perm)
    except:
        break

* 運用內建模組 ```itertools.permutations``` 之解法

from itertools import permutations


while True:
    try:
        # input
        n = int(input())
        
        # process
        perms = tuple(permutations(range(1, n+1), n))[::-1]

        # output
        for perm in perms:
            print(''.join(map(str, perm)))
    except:
        break