Shuffle an Array

Desicription

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();

Solution

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class Solution {
private:
std::vector<int> nums;

public:
Solution(std::vector<int>& nums) {
this->nums = nums;
}

/** Resets the array to its original configuration and return it. */
std::vector<int> reset() {
return nums;
}

/** Returns a random shuffling of the array. */
std::vector<int> shuffle() {
auto ret = std::vector<int>(nums);
for(int i = 0; i < ret.size(); i++) {
int index = rand() % (ret.size() - i);
std::swap(ret[i], ret[i + index]);
}
return ret;
}
};

/**
* 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();
*/