1470. Shuffle the Array.java

/*
Given the array nums consisting of 2n elements in the form [x1,x2,...,xn,y1,y2,...,yn].

Return the array in the form [x1,y1,x2,y2,...,xn,yn].

 

Example 1:

Input: nums = [2,5,1,3,4,7], n = 3
Output: [2,3,5,4,1,7] 
Explanation: Since x1=2, x2=5, x3=1, y1=3, y2=4, y3=7 then the answer is [2,3,5,4,1,7].
Example 2:

Input: nums = [1,2,3,4,4,3,2,1], n = 4
Output: [1,4,2,3,3,2,4,1]
Example 3:

Input: nums = [1,1,2,2], n = 2
Output: [1,2,1,2]
 

Constraints:

1 <= n <= 500
nums.length == 2n
1 <= nums[i] <= 10^3
*/

//SOlution:

class Solution {
    public int[] shuffle(int[] nums, int n) {
        int[] arr = new int[nums.length];
        int k = 0;
        int j = nums.length/2;
        for (int i = 0; i < nums.length/2; i++) {
            arr[k] = nums[i];
            arr[k+1] = nums[j];
            j++;
            k = k+2;
        }
        
        return arr;
        
    }
}

//Another SOlution:
class Solution {
    public int[] shuffle(int[] nums, int n) {
        int[] arr = new int[nums.length];
        int k = 0;
        for (int i = 0,j = nums.length/2; i < nums.length/2; i++,j++) {
            arr[k] = nums[i];
            arr[k+1] = nums[j];
            k = k+2;
        }
        return arr;
        
    }
}

//Another solution:
class Solution {
    public int[] shuffle(int[] nums, int n) {
        int[] ans = new int[2*n];
        int g=0;
        for(int i=0;i<2*n;i++){
            if(i%2==0){
             ans[i] = nums[g++];}
            else{
             ans[i]=nums[g+n-1];}
        }
        return ans;
    }
}