# 384. Shuffle an Array | LeetCode Solution

Given an integer array `nums`, design an algorithm to randomly shuffle the array. All permutations of the array should be equally likely as a result of the shuffling.

Implement the `Solution` class:

• `Solution(int[] nums)` Initializes the object with the integer array `nums`.
• `int[] reset()` Resets the array to its original configuration and returns it.
• `int[] shuffle()` Returns a random shuffling of the array.

Example 1:

```Input
["Solution", "shuffle", "reset", "shuffle"]
[[[1, 2, 3]], [], [], []]
Output
[null, [3, 1, 2], [1, 2, 3], [1, 3, 2]]

Explanation
Solution solution = new Solution([1, 2, 3]);
solution.shuffle();    // Shuffle the array [1,2,3] and return its result.
// Any permutation of [1,2,3] must be equally likely to be returned.
// Example: return [3, 1, 2]
solution.reset();      // Resets the array back to its original configuration [1,2,3]. Return [1, 2, 3]
solution.shuffle();    // Returns the random shuffling of array [1,2,3]. Example: return [1, 3, 2]

```

Constraints:

• `1 <= nums.length <= 50`
• `-106 <= nums[i] <= 106`
• All the elements of `nums` are unique.
• At most `104` calls in total will be made to `reset` and `shuffle`.

The solution to the above question is -

class Solution
{
public:
vector<int> v;
vector<int> org;
Solution(vector<int> &nums)
{
v = nums;
org = nums;
}

vector<int> reset()
{
v = org;
return v;
}

vector<int> shuffle()
{
for (int i = 0; i < v.size(); i++)
{
int r = (rand() % v.size());
swap(v[i], v[r]);
}
return v;
}
};

/**
* 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();
*/