Algorithm problems...

[pabloist]

I'm trying to get the simple first project from http://www.ai-junkie.com/ga/intro/gat3.html done, and I pretty much have the code done and working - except the chromosomes aren't being evaluated correctly. I've stepped through the debugger, and it seems to work but I when try printing sample chromosomes to the console screen, they don't evaluate correctly..

Firstly, is there anything wrong with what I'm doing here?

void Chromosome::CalculateScore()
{
    // Buffer that contains a value corresponding to each 'gene'
    // 0-13, where 0-9 are values and 10, 11, 12, and 13 symbolize operators.
    int buff[CHROMOSOME_MAX_LEN];

    // Are we searching for an operator?
    bool wantOperator = false;
    // Have we found a first value yet?
    bool foundFirstNum = false;

    float ret = 0.f;

    // The code is easier to follow if we read to a buffer first.
    for (int i=0; i<CHROMOSOME_MAX_LEN; i++)
        buff[i] = BinToDec(data_[i].GetString());

    // For every value in the buffer...
    for (int i=0; i<CHROMOSOME_MAX_LEN; i++)
    {
        // Numbers.
        if (buff[i] < 10)
        {
            // Were we looking for an operator?
            if (wantOperator) continue;

            // If this is the first one, let the ret val = the first
            // buffer val.
            if (!foundFirstNum)
            {
                ret = buff[i];
                foundFirstNum = true;
                wantOperator = true;
                continue;
            }

            // Now, let's search for a new value.
            wantOperator = true;
            continue;
        }

        // Operators. Ensure that we won't overstep the array boundary
        // when performing an operand.
        else if ((buff[i] < 14) && ((i+1) < CHROMOSOME_MAX_LEN))
        {
            // If we didn't want an operator, keep going.
            if (!wantOperator) continue;

            // Ensure that we're operating with a value 0-9.
            while (!(i < 10))
                i++;

            // If i does not fall within the bounds of the array, continue.
            if (!(i < CHROMOSOME_MAX_LEN)) continue;

            // We've made sure that we have a valid 2nd parameter for addition.
            switch (buff[i])
            {
                // Otherwise...
                wantOperator = false;

                case 10:
                    ret += buff[i];
                    continue;
                case 11:
                    ret -= buff[i];
                    continue;
                case 12:
                    ret *= static_cast<float>(buff[i]);
                    continue;
                case 13:
                    // To handle div by 0
                    if (buff[i] == 0)
                    {
                        ret += buff[i];
                        continue;
                    }
                    else
                    {
                        ret /= static_cast<float>(buff[i]);
                        continue;
                    }
                default:
                    continue;
            }
        }
        else continue;

    }

    value_ = ret;
}

What is meant to happen is:
Let 0-9 correspond to values.
Let 10, 11, 12, and 13 correspond to +, -, *, and / respectively.
Let 14 and 15 (which are viable numbers because genes are represented in binary)
be invalid and skipped.

The buffer might contain a sequence such as
0 13 12 9 10 3 4 15

Which would translate into
0 / * 9 + 3 4 invalid

The algorithm should be able to interpret this as
0 / 9 + 3
(ignoring order of operations for simplicity's sake)
which would equal three.

I think that maybe I could try incrementing by 2s instead, looking for operators (and checking validity of values index+1 and index-1 instead) but I'm not sure how I could get that to work.

It's possible that there's a problem elsewhere, so if you feel up to it, I posted a compilable version here: http://codepad.org/uRb6SZJZ
(it complains if I try to use auto iter on line 45, but code::blocks rejects Vector<T>::iterator there so I just went with auto)