cppTriangleSquareMadness

    const int size{ 9 };
    int a, b, c, d;
    char input{ 'x' };
    bool positive{ false };
    do
    {
        std::cout << "Enter figure a, b, c, d, e, f, g, h, i, j or x to exit\n";
        std::cin >> input;
        if (input == 'a') { a = -1; b = 1; c = 1; d = 1; }
        else if (input == 'b') { a = -1; b = -1; c = 1; d = -1; }
        else if (input == 'c') { a = -1; b = 1; c = -1; d = 1; }
        else if (input == 'd') { a = 1; b = -1; c = 1; d = -1; }
        else if (input == 'e') { a = -1; b = 1; c = 1; d = -1; }
        else if (input == 'f') { a = -1; b = -1; c = 1; d = 1; }
        else if (input == 'g') { a = -1; b = -1; c = -1; d = -1; }
        else if (input == 'h') { a = 1; b = 1; c = 1; d = 1; }
        else if (input == 'i') { a = -1; b = -1; c = -1; d = 1; }
        else if (input == 'j') { a = 1; b = -1; c = 1; d = 1; }
        else if (input == 'x') { break; }
        else { std::cout << "Incorrect input\n"; continue; };
        for (int y = 0; y < size; ++y)
        {
            for (int x = 0; x < size; ++x)
            {

                //positive = (a * (x + y) >= a * (size - 1) and b * x >= b * y) or (c * (x + y) >= c * (size - 1) and d * x >= d * y);

                positive = ((a * y >= a * (size / 2)) and (b * x >= b * (size / 2))) or ((c * y >= c * (size / 2)) and (d * x >= d * (size / 2)));

                std::cout << ' ' << (positive ? '*' : ' ') << ' ';

            }
            std::cout << '\n';
        }
        std::cout << '\n';
    } while (input != 'x');