在vs2019中使用文件读入功能

#include 
#include 
using namespace std;
int main()
{
	int N;
	ifstream cin("D:\\并行程序设计\\实验四\\矩阵向量乘法.txt");
	cin >> N;
	int count = 0;
	int i = 0 ,j = 0,k=0;
	double ** arr, * ks;
	arr = new double* [N];
	for (int i = 0; i < N; ++i) {
		arr[i] = new double[N];
	}
	for (int i = 0; i < N; ++i)
		for (int j = 0; j < N; ++j)
			cin >> arr[j][i];
	ks = new double[N];
	for (int i = 0; i < N; ++i) cin >> ks[i];

	return 0;
}