Problem 3.1 (10 points) (20 extra points for elegant solution) Write a function W (n) which for a given positive integer n returns a generator with all permutations of the set [0, 1, 2, . . . , n-1] n which for all i 0,1,2,..., . , -1, the number i is not at the ith position E g. For n = 3, there are 3! 1,2, 0) and (2,0,1) 6 permutations [o. 1 2) (0 2, 1), (1, 0, 2. (1, 2 O, (2 0, 1), (2 1 01 And W(3) should return the generator with permutations Write a function w n which for a given positive integer n returns a generator with all permutations of the set 0,1,2, number i is not at the i th position. n-1 in which for all0,1,2, n-1 , the E.g. For n-3, there are 31-6 permutations [(0, 1, 2), (0, 2,1), (1, 0, 2), (1, 2, 0), 2, 0, 1), (2, 1, 0)]. And W(3) should return the generator with permutations (1, 2, 0) and (2, 0, 1)