[Solved] How to count the number of different digits in a number? [closed]

Question

Use sets!

static int NumberOfDigits(int a) {
    return new HashSet<char>(Math.Abs(a).ToString()).Count;
}

We make a into a string and then turn the string into a set of characters. Since sets cannot contain duplicate values, the count of the set is the number of distinct digits.

Accepted Answer

Use sets!

static int NumberOfDigits(int a) {
    return new HashSet<char>(Math.Abs(a).ToString()).Count;
}

We make a into a string and then turn the string into a set of characters. Since sets cannot contain duplicate values, the count of the set is the number of distinct digits.