what c++ input command to detect if user hit "enter" then move on right away

[TGCid]

Basically what the topic said. The user input a string of numbers on one line into an interger array. I am writing a program that sort the inputs in a certain order. I got the sorting part working except there is a forced amount of inputs currently. I can't ask for or assume the amount of number. If I use character array then I can detect when they hit "enter" and stop accepting and move on using cin.get . However the problem is I am not allow to use an a character array and must use an interger array. Is there a way? cin doesn't detect right away but rather till the input has already been completed.