C++ How to check the number of the input from Shell?

Question

below is my C++ code:

void test(int array[], int length) {
    int index;  // the index of heap array that human want to modify
    int num;  // the number of heap in the index position
    cout << "input the index and num" << endl << flush;
    string si,sj;
    try{
        cin >> si >> sj;
        index = stoi(sj);
        num = stoi(si);
    }catch(std::exception e){
        cout << "error, try again" << endl;
        test(array, length);
    }
    if (index <= length && index > 0 && num > 0 && num <= array[index - 1]) {
        array[index - 1] -= num;
        // print(array, length);
    } else {
        cout << "error, try again" << endl;
        test(array, length);
    }
}

And now there is a shell to run this code, but in the shell, there exist input like below:

input the index and num 2 1

this is the correct one

input the index and num 2

it just have 1 value, and the program blocked here to wait for another input, i should figure that out and output "error, try again"

input the index and num 1 2 3

this is also incorrect because there are more than 2 input value. the same, I should figure that out and output "error, try again"

How to deal with this?

Answer 1

You should use cin.getline for your input instead.

Then split the string into substrings and count them.