Shuffle a set of numbers without duplicates.

Example:

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// Init an array with set 1, 2, and 3. int[] nums = {1,2,3}; Solution solution = new Solution(nums); // Shuffle the array [1,2,3] and return its result. Any permutation of [1,2,3] must equally likely to be returned. solution.shuffle(); // Resets the array back to its original configuration [1,2,3]. solution.reset(); // Returns the random shuffling of array [1,2,3]. solution.shuffle(); |

Java Solution

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public class Solution { int[] origin; int[] res; Random r; public Solution(int[] nums) { origin = nums; res = Arrays.copyOf(nums, nums.length); r = new Random(); } /** Resets the array to its original configuration and return it. */ public int[] reset() { res = Arrays.copyOf(origin, origin.length); return res; } /** Returns a random shuffling of the array. */ public int[] shuffle() { int right = res.length - 1; int j; while(right > 0) { j = r.nextInt(right + 1); swap(res, j, right); right--; } return res; } void swap(int[] A, int i, int j) { int tmp = A[i]; A[i] = A[j]; A[j] = tmp; } } /** * Your Solution object will be instantiated and called as such: * Solution obj = new Solution(nums); * int[] param_1 = obj.reset(); * int[] param_2 = obj.shuffle(); */ |

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