Thread: reading from file of unspecified size into array

here is my attempted code so far but i have no idea to declare/read in for an uspecified sized array

Code:

#include <iostream>
#include <fstream>
using namespace std;

int main()
{
	ifstream infile;

	int array[];
	char fileName[21];
	int number;
	int total = 0;
	int nums = 0;

	cout << "Enter a file name: ";
	cin >> fileName;

	infile.open(fileName);






	infile.close();
	
	return 0;
}