Question

Hi. I'm trying to write a program that uses dynamic memory management to create two arrays. splice() must create the third array and return a pointer to main(). Main() must capture the pointer returned from the splice() function.

Sol'n so far, I get the results of the first and second array, but it isn't showing the results of the spliced function:

#include <iostream>

using namespace std;

// Function int* splice() inserts the 2nd array into 1st array starting at int numOfElements
int* splice(int *array1, int *array2, int size1, int size2, int numOfElements)
{
   int *result = new int[size1 + size2];
   for (int i = 0; i < numOfElements; i++)
       *(result + i) = *(array1 + i);
   for (int i = 0; i < size2; i++)
       *(result + numOfElements + i) = *(array2 + i);
   //Line 13 will copy ith element of the second element into numOfElements + ith position in the final array.
   for (int i = numOfElements; i < size1; i++)
       *(result + size2 + i) = *(array1 + i);
   system("pause");
   return result;
}

int main()
{

int size1, size2, numOfElements;
   cout << "Enter the size of the first array: ";
   cin >> size1;
   cout << "Enter the size of the second array: ";
   cin >> size2;
   cout << "Enter the number of elements of the first array to be copied before splice: ";
   cin >> numOfElements;

srand(100);
   int *array1 = new int[size1];
   int *array2 = new int[size2];
   for (int i = 0; i < size1; i++)
       *(array1 + i) = rand() % size1;
   for (int i = 0; i < size2; i++)
       *(array2 + i) = rand() % size2;

cout << "The contents of the first array is: " << endl;
   for (int i = 0; i < size1; i++)
   {
       cout << *(array1 + i) << "\t";
       if ((i + 1) % 10 == 0)
           cout << endl;
   }
   cout << endl << "The contents of the second array is: " << endl;
   for (int i = 0; i < size2; i++)
   {
       cout << *(array2 + i) << "\t";
       if ((i + 1) % 10 == 0)
           cout << endl;
   }
   int *array = splice(array1, array2, size1, size2, numOfElements);

cout << "The contents of the spliced array is: " << endl;
   for (int i = 0; i < size1 + size2; i++)
   {
       cout << *(array + i) << "\t";
       if ((i + 1) % 10 == 0)
           cout << endl;
   }

    delete[] array1;
   delete[] array2;
   delete[] array;

   //the values are deleted, but the pointers still exist
}

Answer 1

#include <iostream>
#include<cstdlib>//modified here
using namespace std;

// Function int* splice() inserts the 2nd array into 1st array starting at int numOfElements
int* splice(int *array1, int *array2, int size1, int size2, int numOfElements)
{
int *result = new int[size1 + size2];
for (int i = 0; i < numOfElements; i++)
*(result + i) = *(array1 + i);
for (int i = 0; i < size2; i++)
*(result + numOfElements + i) = *(array2 + i);
//Line 13 will copy ith element of the second element into numOfElements + ith position in the final array.
for (int i = numOfElements; i < size1; i++)
*(result + size2 + i) = *(array1 + i);
//system("pause");
return result;
}
//everything is fine with your code,apart from including header file
//i provided output screenshot
int main()
{

int size1, size2, numOfElements;
cout << "Enter the size of the first array: ";
cin >> size1;
cout << "Enter the size of the second array: ";
cin >> size2;
cout << "Enter the number of elements of the first array to be copied before splice: ";
cin >> numOfElements;

srand(100);
int *array1 = new int[size1];
int *array2 = new int[size2];
for (int i = 0; i < size1; i++)
*(array1 + i) = rand() % size1;
for (int i = 0; i < size2; i++)
*(array2 + i) = rand() % size2;

cout << "The contents of the first array is: " << endl;
for (int i = 0; i < size1; i++)
{
cout << *(array1 + i) << "\t";
if ((i + 1) % 10 == 0)
cout << endl;
}
cout << endl << "The contents of the second array is: " << endl;
for (int i = 0; i < size2; i++)
{
cout << *(array2 + i) << "\t";
if ((i + 1) % 10 == 0)
cout << endl;
}
int *array = splice(array1, array2, size1, size2, numOfElements);

cout << "\nThe contents of the spliced array is: " << endl;
for (int i = 0; i < size1 + size2; i++)
{
cout << *(array + i) << "\t";
if ((i + 1) % 10 == 0)
cout << endl;
}

delete[] array1;
delete[] array2;
delete[] array;

//the values are deleted, but the pointers still exist
}

output: