关于C++算法中归并排序的问题

求助大神，我写的这个归并排序的代码有什么问题，为什么程序运行后什么也不输出呢？

#include<iostream>
using namespace std;
void erfen(int A[],int low,int high);
void paixu(int A[],int low,int mid,int high);

int main()
{
    int num[2] = {3,4};
    erfen(num, 0,1);
    for (int i = 0; i < 2; i++)
        cout << num[i] << endl;

    return 0;
}
void paixu(int A[], int low, int mid, int high)
{
    int* B = new int[high - low + 1];
    int i = low;
    int j = mid + 1;
    int k = 0;
    while (i <= mid && j <= high)
    {
        if (A[i] <= A[j])B[k++] = A[i++];
        else B[k++] = A[j++];
    }
    while (i <= mid)B[k++] = A[i++];
    while (j <= high) B[k++] = A[j++];
    //填充原数组
    for (int x = low, k = 0; x <= high; i++)
        A[i] = B[k++];
    delete [] B;
}
void erfen(int A[], int low, int high)
{

    if (low < high)
    {
        int mid = (low + high) / 2;
        erfen(A,low,mid);
        erfen(A, mid + 1,high);
        paixu(A, low, mid, high);
    }
}

程序运行后，先是卡住几秒，然后输出“请按任意键继续...”

https://www.cnblogs.com/yinheyi/p/10840465.html