Why am I receiving wrong values (resistor color code calculator)

Question

I want to make a resistor color code calculator but it seems it doesn't work properly. Most combinations seem to return accurate values but whenever I try using gold and silver multipliers, the code returns 0.00. Since gold is 10^-1; shouldn't the code return 22*10^-2 which is 0.22? How can I fix this issue?

typedef enum Color {
    SILVER = -2 ,
    GOLD = -1 ,
    BLACK = 0,
    BROWN,
    RED,
    ORANGE,
    YELLOW,
    GREEN,
    BLUE,
    VIOLET,
    GREY,
    WHITE
} Color;



typedef struct Resistor {
    Color ring1;
    Color ring2;
    Color multiplier;
} Resistor ;

double resistor_calculate_value(Resistor self) {
    return (self.ring1 * 10 + self.ring2) * (unsigned int) pow(10, self.multiplier);
}

int main() {
    Resistor res1;
    res1.ring1 = RED;
    res1.ring2 = RED;
    res1.multiplier = GOLD;

    printf("%f\n", resistor_calculate_value(res1));

    return 0;
}

Answer 1

Don't cast the result of pow() to unsigned int if you want the result to be floating point. Removing the cast gives result 2.2, that is: 22 * 10^-1.

It's generally a very bad idea to mix fixed point and floating point calculations in the same expression. You should ensure that all operands are floating point.