Reading and writing arrays from file

Can someone please help me with a short programme to read and then write a file.

Basically I wish to open a file say "numbers.text"

numbers.txt contains these four number in this order

2 4
3 1

I wish to read them into my app as a(0), a(1), a(2) and a(3)
So a(0)=2, a(1)=4, a(2)=3 and a(3)=1

Next I wish to open a file "order.txt" and write these numbers after sorting as

1 2
3 4.

It is fairly basic but I'm new to C++ and generally trying to teach myself everything from scratch.

Thanks in advance.
closed account (N85iE3v7)
Hey I'd consult

In the last 2 years my coworkers used C library functions to read and write files, so I sort of lost fluency in the C++ way, which is better IMO.
Thank you

After reading that I get the idea but not quite enough.

I can work out how to order the numbers, that's the easy bit. It is just how to read and write number arrays to file.
Reading from a file is very much the same as getting input from the user via cin.
ifstream infile("numbers.txt");
int count = 0;
int a[50]; // allocate more space than is required.

while (infile >> a[count++]); // read all the data into array  

After the while loop ends, count will contain the number of values which were successfully read from the file.
Thanks I'll adapt that into what I have so far. :)
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