algorithm for shuffling elements of an array.

DIRECTORY.md

@@ -866,6 +866,7 @@
   * [Quine](other/quine.py)
   * [Scoring Algorithm](other/scoring_algorithm.py)
   * [Sdes](other/sdes.py)
+  * [Shuffled Array](other/shuffled_array.py)
   * [Tower Of Hanoi](other/tower_of_hanoi.py)
   * [Word Search](other/word_search.py)
 

other/shuffled_array.py

@@ -0,0 +1,71 @@
+# To create a shuffled array. Generate a pseudo random number
+# Swap that number with str_square_seed other element in the list run this
+# swapping len(Array) times to get desired shuffled array
+
+# To Understand more of random number generation
+# follow https://en.wikipedia.org/wiki/Lagged_Fibonacci_generator
+
+import doctest
+import time
+
+
+class Solution:
+    # """
+    # >>> Solution().__init__(array=[1,2,3])
+    # Traceback (most recent call last):
+    #            ....
+    # TypeError: __init__() missing 1 required positional argument: 'array'
+    # """
+
+    def __init__(self, array: list) -> None:
+        self.arr = array
+        self.seed = int(str(time.time())[-1:-5:-1])
+
+    # generating a 4 digit number randomly
+    # by taking the last four numbers of the system generated time
+    # pseudo random number generator
+    def pseudo_random_number_generator(self, num: int) -> int:
+        """
+        >>> Solution([56]).pseudo_random_number_generator(1)
+        0
+        """
+        if num == 1:
+            return 0
+        self.seed *= self.seed
+        str_square_seed = str(self.seed)
+        if str_square_seed != "0":
+            self.seed = int(str_square_seed[-1:-5:-1])
+        else:
+            str_square_seed = str_square_seed[:] + str(len(self.arr) // 2)
+        if int(str_square_seed[-1]) < num:
+            return int(str_square_seed[-1])
+        return self.pseudo_random_number_generator(num)
+
+    def reset(self) -> list:
+        # it will return the original given array
+        """
+        >>> Solution([-7, 0, 4, -56.7]).reset()
+        [-7, 0, 4, -56.7]
+        """
+        return self.arr
+
+    def shuffle(self) -> list:
+        # generated a pseudo number for each traversal
+        # and swapped the traversing value with that number
+        """
+        >>> Solution([2]).shuffle()
+        [2]
+        """
+        temp = self.arr.copy()
+        for i in range(len(self.arr)):
+            a = self.pseudo_random_number_generator(len(self.arr))
+            temp[a], temp[i] = temp[i], temp[a]
+        return temp
+
+
+if __name__ == "__main__":
+    solution_class = Solution([18, 2, 3, 4, 5, 7, 8, 10, 21])
+    shuffled_arr = solution_class.shuffle()
+    print(shuffled_arr)
+
+    doctest.testmod()