The Big Programming Thread - Page 897

char find_first_nonunique_character(string input_string) {
    set<char> characters;

    for (char& c: input_string) {
        if (characters.contains(element)) {
            return element;
        } else {
            characters.insert(element);
        }
    }

    throw IllegalArgumentException("Input only has unique characters");
}

char find_first_unique_character(string input_string) {
    map<char, int> characters_count;

    for (char& c: input_string) {
        if (characters_count.count(c) == 0) {
            characters_count.insert(element, 1);
        } else {
            characters_count[element] += 1;
        }
    }
    
    for (char& c: input_string) {
        if (characters_count.count(c) == 1) {
            return c;
        }
    }

    throw IllegalArgumentException("Input has no unique characters");
}