New Problem Solution - "Shuffle an Array"

README.md

@@ -12,6 +12,7 @@ LeetCode
 |387|[First Unique Character in a String](https://leetcode.com/problems/first-unique-character-in-a-string/) | [C++](./algorithms/cpp/firstUniqueCharacterInAString/FirstUniqueCharacterInAString.cpp)|Easy|
 |386|[Lexicographical Numbers](https://leetcode.com/problems/lexicographical-numbers/) | [C++](./algorithms/cpp/lexicographicalNumbers/LexicographicalNumbers.cpp)|Medium|
 |385|[Mini Parser](https://leetcode.com/problems/mini-parser/) | [C++](./algorithms/cpp/miniParser/MiniParser.cpp)|Medium|
+|384|[Shuffle an Array](https://leetcode.com/problems/shuffle-an-array/) | [C++](./algorithms/cpp/shuffleAnArray/ShuffleAnArray.cpp)|Medium|
 |377|[Combination Sum IV](https://leetcode.com/problems/combination-sum-iv/) | [C++](./algorithms/cpp/combinationSumIV/combinationSumIV.cpp)|Medium|
 |376|[Wiggle Subsequence](https://leetcode.com/problems/wiggle-subsequence/) | [C++](./algorithms/cpp/wiggleSubsequence/wiggleSubsequence.cpp)|Medium|
 |350|[Intersection of Two Arrays II](https://leetcode.com/problems/intersection-of-two-arrays-ii/) | [C++](./algorithms/cpp/intersectionOfTwoArraysII/intersectionOfTwoArraysII.cpp)|Easy|

algorithms/cpp/shuffleAnArray/ShuffleAnArray.cpp

@@ -0,0 +1,59 @@
+// Source : https://leetcode.com/problems/shuffle-an-array/
+// Author : Hao Chen
+// Date : 2016-08-24
+
+/*************************************************************************************** 
+ *
+ * Shuffle a set of numbers without duplicates.
+ * 
+ * Example:
+ * 
+ * // 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();
+ ***************************************************************************************/
+
+class Solution {
+public:
+ Solution(vector<int> nums) : _nums(nums), _solution(nums) {
+ srand(time(NULL));
+ }
+
+ /** Resets the array to its original configuration and return it. */
+ vector<int> reset() {
+ return _solution = _nums;
+ }
+
+ /** Returns a random shuffling of the array. */
+ vector<int> shuffle() {
+ //Fisher Yates
+ //https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle
+
+ int i = _solution.size();
+
+ while ( --i > 0 ) {
+ int j = rand() % (i+1);
+ swap(_solution[i], _solution[j]);
+ }
+ return _solution;
+ }
+private:
+ vector<int> _nums, _solution;
+};
+
+/**
+ * Your Solution object will be instantiated and called as such:
+ * Solution obj = new Solution(nums);
+ * vector<int> param_1 = obj.reset();
+ * vector<int> param_2 = obj.shuffle();
+ */