Output Console freeze after entering the input

Question

I have been trying to code to find the LCM of given Array elements. My code looks like this

public long LcmOfArray(List<int> a)
{
    long LCM = 1;
    bool divisible = false;
    int divisor = 2, count = 0;

    while (count != a.Count)
    {
        for (int i = 0; i < a.Count; i++)
        {
            if (a[i] == 0)
            {
                return 0;
            }
            if (a[i] < 0)
            {
                a[i] *= -1;
            }
            if (a[i] % divisor == 0)
            {
                divisible = true;
                a[i] /= divisor;
            }
            if (a[i] == 1)
            {
                count++;
            }
        }

        if (divisible)
        {
            LCM *= divisor;
        }
        else
        {
            divisor++;
        }
    }
    
    return LCM;
}

My problem is that the output console freeze as I enter the input. I have tried another method without the while loop. That is, eliminated while loop and added an if loop in the end.

if (count == a.Count)
{
    return LCM;
}

But now compiler throws an error stating that not all code path returns a value. Can somebody help me with what is wrong in my code? I am a beginner in coding. Thanks in advance!!

Answer 1

You should place bool divisible = false; and int count = 0; in the while loop. And since you can't place int count = 0; out of the while loop you should use while (true) instead of while (count != a.Count) and place the following if statement in the last of the while loop.

if (count == a.Count)
{
    return LCM;
}

Here's the full method :

public static long LcmOfArray(List<int> a)
{
    long LCM = 1;
    int divisor = 2;

    while (true)
    {
        int count = 0;
        bool divisible = false;
        for (int i = 0; i < a.Count; i++)
        {
            if (a[i] == 0)
            {
                return 0;
            }
            if (a[i] < 0)
            {
                a[i] *= -1;
            }
            if (a[i] == 1)
            {
                count++;
            }
            if (a[i] % divisor == 0)
            {
                divisible = true;
                a[i] /= divisor;
            }
        }
        if (divisible)
        {
            LCM *= divisor;
        }
        else
        {
            divisor++;
        } 
        if (count == a.Count)
        {
            return LCM;
        }
    }
}