Новый массив из общих элементов других массивов

int main() {
    const int n = 5, m = 5;
    int *a = new int[n], *b = new int[m];
    for (int i = 0; i < n; i++)
        cin >> a[i];
    for (int i = 0; i < m; i++)
        cin >> b[i];
    int *c = new int[n+m];
    for (int i = 0; i < n+m; i++)
        if (a[i] = b[i])
            c[i] = a[i];
    for (int i = 0; i < n + m; i++)
        cout << c[i];
 
    delete []a;
    delete []b;
    delete []c;
}

#include <iostream>
 
using namespace std;
 
int main() {
 
    const int n = 5, m = 5;
 
    int *a = new int[n], *b = new int[m];
 
    for (int i = 0; i < n; i++)
    cin >> a[i];
 
    for (int i = 0; i < m; i++)
    cin >> b[i];
 
    int *c = new int[n+m];
 
    for (int i = 0; i<n; i++) 
        c[i] = a[i];
 
    for (int i=0; i<m; i++) 
        c[i+n] = b[i];
 
    for (int i = 0; i < n + m; i++)
        cout << c[i];
 
    delete []a;
    delete []b;
    delete []c;
 
    system("pause");
    return 0;
}

#include <iostream>
#include <ctime> 
#include <cstdlib> 
using namespace std;
 
int main()
{
    srand(time(nullptr));
    int m, n;
    cout << "Enter size of array A: ";
    cin >> n;
    cout << "Enter size of array B: ";
    cin >> m;
    int *A = new int[n];
    int *B = new int[m];
    int min_length = m < n ? m : n;
    int *C = new int[min_length];
    cout << "Array A:" << endl;
    for (int i = 0; i<n; i++)
    {
        A[i] = rand() % 3;
        cout << A[i] << " ";
    }
    cout << endl << "Array B:" << endl;
    for (int i = 0; i<m; i++)
    {
        B[i] = rand() % 3;
        cout << B[i] << " ";
    }
    int size_c = 0;
    for (int i = 0; i < min_length; i++)
    {
        if (A[i]==B[i])
            C[size_c++] = A[i];
    }
    cout << endl << "Array C:" << endl;
    for (int i = 0; i < size_c; i++)
        cout << C[i] << " ";
    delete[]A;
    delete[]B;
    delete[]C;
    return 0;
}