Положительные и отрицательные элементы матрицы переписать в разные массивы

#include <iostream>
#include <vector>
 
using namespace std;
 
int main() {
    int m, n;
    cin >> m >> n; // Input the dimensions of the matrix
 
    vector<int> A; // Create a vector to store the elements of the matrix
    int element;
    for (int i = 0; i < m * n; i++) {
        cin >> element;
        A.push_back(element);
    }
 
    vector<int> B; // Create a vector to store positive elements
    vector<int> C; // Create a vector to store negative elements
    for (int i = 0; i < m * n; i++) {
        if (A[i] > 0) {
            B.push_back(A[i]);
        } else {
            C.push_back(A[i]);
        }
    }
 
    cout << "Positive elements count: " << B.size() << endl;
    cout << "Negative elements count: " << C.size() << endl;
 
    return 0;
}

#include <iostream>
 
void print(int *arr, std::size_t n)
{
    for (int i = 0; i < n; i++) {
        std::cout << arr[i] << " ";
    }
}
 
int main()
{
    std::size_t n{3}, m{3}, count_b{0}, count_c{0};
 
    //std::cout << "input sizes: ";
    //std::cin >> n >> m;
 
    int **a, *b, *c;
 
    std::cout << "input elements:\n";
    a = new int*[n];
    for (int i = 0; i < n; i++) {
        a[i] = new int[m];
        for (int j = 0; j < m; j++) {
            std::cin >> a[i][j];
            if (a[i][j] > 0) count_b++;
            else
            if (a[i][j] < 0) count_c++;
        }
    }
 
    if (count_b) b = new int[count_b];
    if (count_c) c = new int[count_c];
 
    int pos_idx{0}, neg_idx{0};
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (a[i][j] > 0) b[pos_idx++] = a[i][j];
            else
            if (a[i][j] < 0) c[neg_idx++] = a[i][j];
        }
    }
 
    std::cout << "B: ";
    print(b, count_b);
    std::cout << "\n";
 
    std::cout << "C: ";
    print(c, count_c);
    std::cout << "\n";
    
    std::cout << "Positive elements count: " << count_b << "\n";
    std::cout << "Negative elements count: " << count_c << "\n";
 
    for (int i = 0; i < n; i++) delete[] a[i];
    delete[] a;
    delete[] b;
    delete[] c;
 
    return 0;
}