Problem #32

I avoided doing this one for quite some time because I didnt really know where to begin. But once I started it, it was fairly easy (got the correct answer on my first try).

#include <iostream>
#include <string>

using namespace std;

bool isThisANumberWeAreLookingFor (int, int, int);

int main()
{
    int total = 0;
    int fullList[32];
    int count = 0;

// we want one times four, and two times three, so:
    for (unsigned int i = 0; i < 100; i++)
        for (unsigned int j = 100; j < 10000; j++)
            if (isThisANumberWeAreLookingFor (i, j, i*j))
                fullList[count++] = i * j;
            else
            {
                // This is not the number you are looking for ... move along
            }

    for (unsigned int i = 0; i < count; i++)
        for (unsigned int j = i + 1; j < count; j++)
            if (fullList[i] == fullList[j])
                fullList[j] = 0;

    for (unsigned int i = 0; i < count; i++)
        total += fullList[i];

    cout << total << endl;

    system ("pause");
    return 0;
}

bool isThisANumberWeAreLookingFor (int a, int b, int c)
{
    char buffer[16];
    string str;
    bool found = false;
    bool totalFound = true;

    sprintf (buffer, "%i%i%i", a, b, c);
    str = buffer;

    if (str.size() != 9)
        return false;
    
    totalFound = true;
    for (unsigned int i = 1; i <= 9; i++)
    {
        found = false;

        for (unsigned int j = 0; j < str.size(); j++)
            if (str[j] == i + '0')
            {
                found = true;
                break;
            }
        if (found == false)
        {
            totalFound = false;
            break;
        }
    }

    return totalFound;
}