Counting the decimal places in a double | Floating point arithmetic in C

Question

I have a program in C that has to remove all decimal places of a variable by multiplying it with 10^(numberOfDecimalPlaces). I have written the following function to count decimal places:

int getDecimalPlaces(double n)
{
    int numberOfDecimalPlaces = 0;
    for (numberOfDecimalPlaces = 0; n != (int) n; n *= 10)
        numberOfDecimalPlaces++;
    return numberOfDecimalPlaces;
}

The problem is that when I am passing 1.4 to the function, it handles it as 1.399999999... because of floating point arithmetic. Do you know a way to still count the number of decimal places with a simple algorithm without having to worry about floating point precision? Thanks in advance. Using sprintf, that can be fixed.

#define MAX_STRING 256

typedef enum
{
    false, true
} bool;

int getDecimalPlaces(double n)
{
    char string[MAX_STRING];
    sprintf(string, "%f", n);
    int numberOfDecimalPlaces = 0;
    int i; // index of \0
    for (i = 0; i < MAX_STRING; ++i)
        if (string[i] == '\0')
            break;
    bool countZero = false;
    for (int j = i-1; j > 0; j--)
    {
        if (string[j] == '.')
            break;
        if (!countZero && string[j] != 48)
            countZero = true;
        if (countZero)
            numberOfDecimalPlaces++;
    }
    return numberOfDecimalPlaces;
}