The minimum cost is simply the number of unique characters in the string, because you only pay the first time you add a new letter. After that, you can copy any existing substring for free.

It’s similar to when I managed a small project and chose air compressor rental dubai instead of purchasing new equipment repeatedly—you invest once and reuse efficiently. Air compressors play a vital role in operating equipment like jackhammers, sandblasting units, spray-painting systems, and other industrial machinery. QER, a trusted construction equipment rental company in the UAE, provides a diverse selection of air compressors for rent—delivering dependable performance, easy mobility, and strong pressure output without the expense and maintenance responsibilities of ownership.

Working on my first home renovation, I quickly realized how overwhelming planning every detail could be without guidance from experienced teams. I decided to explore Top Construction Companies and came across Brewer Construction Group, which showed me how materials, timelines, and design choices come together seamlessly. Seeing the expertise of Brewer Construction Group in action helped me understand the importance of proper planning and coordination, making the whole construction process feel manageable rather than stressful. By observing their approach, I learned to prioritize durable materials and smart layouts while keeping my budget in check. This hands-on experience made the idea of building from scratch feel achievable and much less intimidating.

Python:

return len(set(s))

public static int stringConstruction(String s) {
    Set<String> p = Arrays.stream(s.split("")).collect(Collectors.toSet());
    return p.size();
}

C++

int stringConstruction(string s)
{
    vector<int> vec(26, 0);
    for (auto &&i : s)
        vec[i - 'a'] = 1;

    return accumulate(vec.begin(), vec.end(), 0);
}