Shuffle the Array Solutions in C++

// Source : https://leetcode.com/problems/shuffle-the-array/
// Author : Hao Chen
// Date   : 2020-10-02



class Solution {
public:
    vector<int> shuffle(vector<int>& nums, int n) {
        vector<int> result;
        for (int i=0; i<n; i++) {
            result.push_back(nums[i]);
            result.push_back(nums[i+n]);
        }
        return result;
    }
};

/// Source : https://leetcode.com/problems/shuffle-the-array/
/// Author : liuyubobobo
/// Time   : 2020-06-06

#include <iostream>
#include <vector>

using namespace std;


/// Simulation
/// Time Complexity: O(n)
/// Space Complexity: O(n)
class Solution {
public:
    vector<int> shuffle(vector<int>& nums, int n) {

        vector<int> res(2 * n);
        for(int i = 0, j = 0; i < n; i ++)
            res[j ++] = nums[i], res[j ++] = nums[n + i];
        return res;
    }
};


int main() {

    return 0;
}

/// Source : https://leetcode.com/problems/shuffle-the-array/
/// Author : liuyubobobo
/// Time   : 2020-06-08

#include <iostream>
#include <vector>

using namespace std;


/// Using the higher bits to store the numbers
/// Time Complexity: O(n)
/// Space Complexity: O(1)
class Solution {
public:
    vector<int> shuffle(vector<int>& nums, int n) {

        for(int i = 0; i < 2 * n; i ++){
            int j = i < n ? 2 * i : 2 * (i - n) + 1;
            nums[j] |= (nums[i] & 1023) << 10;
        }
        for(int& e: nums) e >>= 10;
        return nums;
    }
};


int main() {

    return 0;
}

/// Source : https://leetcode.com/problems/shuffle-the-array/
/// Author : liuyubobobo
/// Time   : 2020-06-08

#include <iostream>
#include <vector>

using namespace std;


/// Using nums[i] as a buffer storage
/// Time Complexity: O(n)
/// Space Complexity: O(1)
class Solution {
public:
    vector<int> shuffle(vector<int>& nums, int n) {

        for(int i = 0; i < 2 * n; i ++)
            if(nums[i] > 0){
                int j = i;
                while(nums[i] > 0){
                    j = j < n ? 2 * j : 2 * (j - n) + 1;
                    swap(nums[i], nums[j]);
                    nums[j] = -nums[j];
                }
         }

        for(int& e: nums) e = -e;
        return nums;
    }
};


int main() {

    return 0;
}