# Merging elements of two different arrays alternatively in third array

Given two arrays arr1[] and arr2[], we need to combine two arrays in such a way that the combined array has alternate elements of both. If one array has extra element, then these elements are appended at the end of the combined array.

```Input : arr1[] = {1, 2, 3, 4, 5, 6}
arr2[] = {11, 22, 33, 44}
Output: {1, 11, 2, 22, 3, 33, 4, 44, 5, 6}

Input : arr1[] = {1, 2, 3, 4, 5, 6, 7, 8}
arr2[] = {11, 22, 33, 44}
Output: {1, 11, 2, 22, 3, 33, 4, 44, 5, 6, 7, 8}```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

We traverse both given arrays and one by one put their elements into combined array. After one of the arrays is exhausted, we put remaining elements of other array.

## C++

 `// C++ program to merge two sorted arrays/ ` `#include ` `using` `namespace` `std; ` ` `  `// Alternatively merge arr1[0..n1-1] and arr2[0..n2-1] ` `// into arr3[0..n1+n2-1] ` `void` `alternateMerge(``int` `arr1[], ``int` `arr2[], ``int` `n1, ` `                    ``int` `n2, ``int` `arr3[]) ` `{ ` `    ``int` `i = 0, j = 0, k = 0; ` ` `  `    ``// Traverse both array ` `    ``while` `(i

## Java

 `// Java program to merge two sorted arrays ` `import` `java.io.*; ` ` `  `class` `GFG { ` `     `  `    ``// Alternatively merge arr1[0..n1-1] and  ` `    ``// arr2[0..n2-1] into arr3[0..n1+n2-1] ` `    ``static` `void` `alternateMerge(``int` `arr1[], ``int` `arr2[],  ` `                               ``int` `n1, ``int` `n2, ``int` `arr3[]) ` `    ``{ ` `        ``int` `i = ``0``, j = ``0``, k = ``0``; ` `     `  `        ``// Traverse both array ` `        ``while` `(i < n1 && j < n2) ` `        ``{ ` `            ``arr3[k++] = arr1[i++]; ` `            ``arr3[k++] = arr2[j++]; ` `        ``} ` `     `  `        ``// Store remaining elements of first array ` `        ``while` `(i < n1) ` `            ``arr3[k++] = arr1[i++]; ` `     `  `        ``// Store remaining elements of second array ` `        ``while` `(j < n2) ` `            ``arr3[k++] = arr2[j++]; ` `    ``} ` `     `  `    ``// Driver code ` `    ``public` `static` `void` `main(String args[]) ` `    ``{ ` `        ``int` `arr1[] = {``1``, ``3``, ``5``, ``7``, ``9``, ``11``}; ` `        ``int` `n1 = arr1.length; ` `     `  `        ``int` `arr2[] = {``2``, ``4``, ``6``, ``8``}; ` `        ``int` `n2 = arr2.length; ` `     `  `        ``int` `arr3[] = ``new` `int``[n1+n2]; ` `        ``alternateMerge(arr1, arr2, n1, n2, arr3); ` `     `  `        ``System.out.println(``"Array after merging"``); ` `        ``for` `(``int` `i = ``0``; i < n1 + n2; i++) ` `            ``System.out.print( arr3[i] + ``" "``); ` `    ``} ` `} ` ` `  `// This code is contributed  ` `// by Nikita Tiwari. `

## Python3

 `# Python3 program to merge two sorted arrays/ ` ` `  `# Alternatively merge arr1[0..n1-1] and  ` `# arr2[0..n2-1] into arr3[0..n1 + n2-1] ` `def` `alternateMerge(arr1, arr2, n1, n2, arr3) : ` `    ``i ``=` `0``; j ``=` `0``; k ``=` `0` ` `  `    ``# Traverse both array ` `    ``while` `(i < n1 ``and` `j < n2) : ` `        ``arr3[k] ``=` `arr1[i] ` `        ``i ``+``=` `1` `        ``k ``+``=` `1` `         `  `        ``arr3[k] ``=` `arr2[j] ` `        ``j ``+``=` `1` `        ``k ``+``=` `1` `     `  ` `  `    ``# Store remaining elements of first array ` `    ``while` `(i < n1) : ` `        ``arr3[k] ``=` `arr1[i] ` `        ``i ``+``=` `1` `        ``k ``+``=` `1` ` `  `    ``# Store remaining elements of second array ` `    ``while` `(j < n2) : ` `        ``arr3[k] ``=` `arr2[j] ` `        ``k ``+``=` `1` `        ``j ``+``=` `1` `         `  `         `  `# Driver code ` `arr1 ``=` `[``1``, ``3``, ``5``, ``7``, ``9``, ``11``] ` `n1 ``=` `len``(arr1) ` ` `  `arr2 ``=` `[``2``, ``4``, ``6``, ``8``] ` `n2 ``=` `len``(arr2) ` ` `  `arr3``=` `[``0``] ``*``(n1 ``+` `n2) ` `alternateMerge(arr1, arr2, n1, n2, arr3) ` ` `  `print``(``"Array after merging"``) ` `for` `i ``in` `range``(``0``, (n1 ``+` `n2)) : ` `    ``print``(arr3[i] , end ``=` `" "``) ` ` `  `# This code is contributed by Nikita Tiwari. `

## C#

 `// C# program to merge two sorted arrays ` `using` `System; ` ` `  `class` `GFG { ` `     `  `    ``// Alternatively merge arr1[0..n1-1] ` `    ``// and arr2[0..n2-1] into arr3[0..n1+n2-1] ` `    ``static` `void` `alternateMerge(``int` `[]arr1, ``int` `[]arr2, ` `                           ``int` `n1, ``int` `n2, ``int` `[]arr3) ` `    ``{ ` `        ``int` `i = 0, j = 0, k = 0; ` `     `  `        ``// Traverse both array ` `        ``while` `(i < n1 && j < n2) ` `        ``{ ` `            ``arr3[k++] = arr1[i++]; ` `            ``arr3[k++] = arr2[j++]; ` `        ``} ` `     `  `        ``// Store remaining elements of first array ` `        ``while` `(i < n1) ` `            ``arr3[k++] = arr1[i++]; ` `     `  `        ``// Store remaining elements of second array ` `        ``while` `(j < n2) ` `            ``arr3[k++] = arr2[j++]; ` `    ``} ` `     `  `    ``// Driver code ` `    ``public` `static` `void` `Main() ` `    ``{ ` `        ``int` `[]arr1 = ``new` `int``[]{1, 3, 5, 7, 9, 11}; ` `        ``int` `n1 = arr1.Length; ` ` `  `        ``int` `[]arr2 = ``new` `int``[]{2, 4, 6, 8}; ` `        ``int` `n2 = arr2.Length; ` ` `  `        ``int` `[]arr3= ``new` `int``[n1 + n2]; ` `        ``alternateMerge(arr1, arr2, n1, n2, arr3); ` ` `  `        ``Console.WriteLine(``"Array after merging"``); ` `        ``for` `(``int` `i = 0; i < n1+n2; i++) ` `            ``Console.Write(arr3[i] + ``" "``); ` `    ``}  ` `} ` ` `  `// This code is contributed by Sam007. `

## PHP

 ` `

Output :

```Array after merging
1 2 3 4 5 6 7 8 9 11 ```

Time Complexity : O(n1 + n2)

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