合并排序算法 在一个条件下合并第三个数组中的两个数组

这是一种在特定条件下合并两个数组的算法。 它首先比较两个数组的索引，如果 arrayP1 的索引等于 arrayP2 的索引，它将该特定索引存储到答案数组中。任何人都可以帮助在C ++中翻译此算法吗

#include <iostream>
#include <cstdlib>
#include <conio.h>
using namespace std;
int main()
 { 
int sizeofarray=0,i=0 ,j=0, num=0, answers[]={};
cout<<"enter the size of array"<<endl;
cin>>sizeofarray;//take size of array from user
int array1[sizeofarray];
int array2[sizeofarray];
cout<<"please enter a sorted array member of Array1"<<endl;
//input of array element 
for ( i=0 ; i<=sizeofarray; i++)
{
cin>>array1[i];
}
system("CLS");
cout<<"please enter a sorted array member of Array2"<<endl;
for (j=0 ; j<=sizeofarray; j++)
{
cin>>array2[j];
}
 ***strong text***system("CLS");
//comparing the array element and storing the similar items to another         array
while(array1[i]!=NULL && array2[j]!=NULL){
if(array1[i]==array2[j]){
answer[num++]=array1[i];
i++;
j++;
}
else if(array1[i]<array2[j])
{
i++;
}else{
  j++;
   }
 i++;
 j++;
 }
 cout<<"The number of common elements"<<num<<endl;
 cout<<"These are the common numbers: ";
 for (int k=0;k<num;k++){
cout<<answer[k]<<" ";
 }
 getch();
 return 0;
 }