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| 1 | +# To create a shuffled array. Generate a pseudo random number |
| 2 | +# Swap that number with any other element in the list run this swapping len(Array) |
| 3 | +# times to get desired shuffled array |
| 4 | + |
| 5 | +# To Understand more of random number generation |
| 6 | +# follow https://en.wikipedia.org/wiki/Lagged_Fibonacci_generator |
| 7 | + |
| 8 | +# import doctest |
| 9 | +import time |
| 10 | + |
| 11 | + |
| 12 | +class Solution: |
| 13 | + |
| 14 | + """ |
| 15 | + >>> Solution().__init__(array=[1,2,3]) |
| 16 | + Traceback (most recent call last): |
| 17 | + .... |
| 18 | + TypeError: __init__() missing 1 required positional argument: 'array' |
| 19 | + """ |
| 20 | + |
| 21 | + def __init__(self, array: list) -> None: |
| 22 | + self.arr = array |
| 23 | + self.seed = int(str(time.time())[-1:-5:-1]) |
| 24 | + |
| 25 | + # generating a 4 digit number randomly |
| 26 | + # by taking the last four numbers of the system generated time |
| 27 | + # pseudo random number generator |
| 28 | + def prng(self, num: int) -> int: |
| 29 | + """ |
| 30 | + >>> Solution([56]).prng(1) |
| 31 | + 0 |
| 32 | + """ |
| 33 | + if num == 1: |
| 34 | + return 0 |
| 35 | + self.seed *= self.seed |
| 36 | + any = str(self.seed) |
| 37 | + if any != "0": |
| 38 | + self.seed = int(any[-1:-5:-1]) |
| 39 | + else: |
| 40 | + any = any[:] + str(len(self.arr) // 2) |
| 41 | + if int(any[-1]) < num: |
| 42 | + return int(any[-1]) |
| 43 | + return self.prng(num) |
| 44 | + |
| 45 | + def reset(self) -> list: |
| 46 | + # it will return the original given array |
| 47 | + """ |
| 48 | + >>> Solution([2,3,4,56]).reset() |
| 49 | + [2, 3, 4, 56] |
| 50 | + """ |
| 51 | + return self.arr |
| 52 | + |
| 53 | + def shuffle(self) -> list: |
| 54 | + # generated a pseudo number for each traversal |
| 55 | + # and swapped the traversing value with that number |
| 56 | + """ |
| 57 | + >>> Solution([2]).shuffle() |
| 58 | + [2] |
| 59 | + """ |
| 60 | + temp = self.arr.copy() |
| 61 | + for i in range(len(self.arr)): |
| 62 | + a = self.prng(len(self.arr)) |
| 63 | + temp[a], temp[i] = temp[i], temp[a] |
| 64 | + return temp |
| 65 | + |
| 66 | + |
| 67 | +solclass = Solution([18, 2, 3, 4, 5, 7, 8, 10, 21]) |
| 68 | +shuffled_arr = solclass.shuffle() |
| 69 | +print(shuffled_arr) |
| 70 | + |
| 71 | +# doctest.testmod() |
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