cpp-data-structures-array-merge.cpp

#include <iostream>

using namespace std;

// append, concat, compare, copy, merge


struct Array
{
	int A[10];
	int size;
	int length;

};

void Display(struct Array arr)						// function to display the array's elements
{
	int i;
	cout << "Elements are";
	for (i = 0; i < arr.length; i++)
		cout << " " << arr.A[i];
	cout << endl;
}


struct Array* Merge(struct Array* arr1, struct Array *arr2) 
{
	int i, j, k;										// arr1 uses i, arr2 uses j, arr3 uses k
	i = j = k = 0;
	struct Array* arr3 = new Array;						// creating third array in Heap

	while (i < arr1->length && j < arr2->length)		
	{
		if (arr1->A[i] < arr2->A[j])					// checks for smaller value in arr1/arr2
			arr3->A[k++] = arr1->A[i++];				// moves that value to third array
		else
			arr3->A[k++] = arr2->A[j++];				// otherwise move arr2 to arr 3 element
	}
	for (; i < arr1->length; i++)						// keep checking length of arr1
		arr3->A[k++] = arr1->A[i];						// move remaining arr1 elements to arr3
	for (; j < arr2->length; j++)
		arr3->A[k++] = arr2->A[j];						// move remaining arr2 elements to arr3
	arr3->length = arr1->length + arr2->length;			// arr3 length is arr1 + arr 2
	arr3->size = arr1->size + arr2->size;

	return arr3;
}



int main() {


	struct Array arr1 = { {2,6,10,15,25},10,5 };
	struct Array arr2 = { {3,4,8,18,22},10,5 };
	struct Array* arr3;											// used to make an empty array from Merge

	arr3=Merge(&arr1, &arr2);									// assigning arr3

	Display(*arr3);												// Display takes call by value so use *

	return 0;

}