即使 if 为真，为什么 if 语句始终是 else 部分？

Question

I'm having a problem with the if statement at the end. **if the sum of the cubs of the number a user inputs, is equal to the number itself, say "....". Else, say "....." **

The problem is that it always jumps the if part to the else.

Its a task from the uni, no homework or nothing, just training. IF you have suggestions on how to better I would appreciate that too.

Thank you!

{
    int n;  

    cout << "Write a number different from 0 -> ";
    cin >> n;
    
    while (n == 0) 
    {
        cout << "Choose another number -> ";
        cin >> n;
    }

    cout << "Good number " << n << " is!" << "\n";
    cout << "lets separate each digit:" << "\n" << " -----------------------------------" << endl;
    Sleep(1000);
    
    vector<int> vecN;

    while (n != 0)
    {
        int digit = n % 10;
        n /= 10;
        cout << n << endl;
        cout << "Digit: " << digit << endl;
        vecN.push_back(digit);
        Sleep(750);
    }
    cout << "There you go!" << endl;
    Sleep(1000);
    cout << "Next stage, let's find the cubes for each one of the digits!" << endl;
    Sleep(2500);
    
    vector<int> sums;

    for (auto i = vecN.begin(); i != vecN.end(); i++)
    {
        Sleep(500);
        int Cubes = pow(*i, 3);
        
        cout << Cubes << endl;
        sums.push_back(Cubes);
    }

    Sleep(1300);
    cout << "Now let's sum the cubs and see if the number is an Armstrong Number" << endl;
    Sleep(3000);

    int armSum = accumulate(sums.begin(), sums.end(), 0);

    if ( armSum == n )
    {
        cout << "Sum: " << armSum << endl;
        Sleep(500);
        cout << "That's an Armstrong Number!" << "\n"
            "The sum of the cubs of each digit in the number is equal to that same number!" << endl;
    }
    else
    {
        cout << "Sum: " << armSum << endl;
        Sleep(500);
        cout << "That's not an Armstrong Number!" << endl;
    }
        
    return 0;
} ```

Answer 1

When the if -part is entered, the else -part won't be entered any more. Note that your if/else is not surrounded by a loop. So when control passes by once, eg when having entered n==0 , then it has passed by and won't step into neither the if nor the else -part a second time.

Try something like

while (n==0) {
    cout << "Choose another number -> ";
    cin >> n;
}

// continue here; n is != 0