[name] indicated: on line 20, uniq does not contain the number of unique characters, but something else. What exactly?

On line 20, the variable uniq does not contain the number of unique characters, but rather a slice or a map that stores the unique characters themselves or their frequencies, not their count.

For example, if uniq is a map[rune]bool or map[rune]int, it reflects the unique characters or their number of occurrences, but not the number of unique characters directly. To get the count of unique characters, you need to take the length of this structure, for example:

uniq := make(map[rune]bool)
// ... fill uniq
count := len(uniq) // number of unique characters

If uniq is just a variable, then perhaps it contains not a number, but, for example, the last unique character or other information that is not the number of unique characters.