Return to Answer

#include <iostream>
#include <string>
#include <sstream>
#include <string_view>
#include <map>

int main()
{
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(NULL);

    std::string line;
    std::getline(std::cin, line);
    std::stringstream linestream(std::move(line));

    int n, q;
    if (!(linestream >> n >> q) {
       throw std::runtime_error("Fail 1");
    }

    std::string s;
    std::getline(std::cin, s);

    std::map<std::string_view, int> memo;

    for(int loop = 0; loop < q; loop++){
        line.clear();
        std::getline(std::cin, line);
        std::stringstream linestream(std::move(line));

        int l,r, length;
        if (!(linestream >> l >> r)) {
            throw std::runtime_error("Fail 2");
        }

        std::string_view key(&s[l], (r - l + 1));

        auto find = memo.find(key);
        if (find == memo.end()) {
            length = 0;
            for(auto val: key) {
                // Not sure about this.
                // Need some unit tests.
                length += std::islower(val) ? val - 'a' + 1: 0;
            }
            memo[key] = length;
        }
        else {
            length = find->second;
        }
        std::cout << length << "\n";
    }
}

#include <iostream>
#include <string>
#include <sstream>
#include <string_view>
#include <map>

int main()
{
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(NULL);

    std::string line;
    std::getline(std::cin, line);
    std::stringstream linestream(std::move(line));

    int n, q;
    if (!(linestream >> n >> q) {
       throw std::runtime_error("Fail 1");
    }

    std::string s;
    std::getline(std::cin, s);

    // Personally, I need convincing this is a valid optimization
    // creating the tree is relatively trivial but still far
    // more costly than summing a set of integers. You would
    // have to have some long strings and lots of repeats before
    // this becomes worth it.

    // Also this technical could be improved by allowing for
    // totally enclosed substrings to be used in calculating the
    // length for larger strings. 
    std::map<std::string_view, int> memo;

    for(int loop = 0; loop < q; loop++){
        line.clear();
        std::getline(std::cin, line);
        std::stringstream linestream(std::move(line));

        int l,r, length;
        if (!(linestream >> l >> r)) {
            throw std::runtime_error("Fail 2");
        }

        std::string_view key(&s[l], (r - l + 1));

        auto find = memo.find(key);
        if (find == memo.end()) {
            length = 0;
            for(auto val: key) {
                // Not sure about this.
                // Need some unit tests.
                length += std::islower(val) ? val - 'a' + 1: 0;
            }
            memo[key] = length;
        }
        else {
            length = find->second;
        }
        std::cout << length << "\n";
    }
}

I know coding sites say use it. But don't. Its not standard. It will get you into bad habbits that will kick you in the butt one day.

Bad habit. Can get you band from projects.

You just did a find (after creating the substring). Now you are creating the substring agains and repeating the search to get the value! The call to find above returns an iterator you can get the length from the iterator!

I know coding sites say use it. But don't. Its not standard. It will get you into bad habits that will kick you in the butt one day.

Bad habit. Can get you banned from projects.

You just did a find (after creating the substring). Now you are creating the substring again and repeating the search to get the value! The call to find above returns an iterator you can get the length from the iterator!

#include <iostream>
#include <string>
#include <sstream>
#include <string_view>
#include <map>

int main()
{
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(NULL);

    std::string line;
    std::getline(std::cin, line);
    std::stringstream linestream(std::move(line));

    int n, q;
    if (!(linestream >> n >> q) {
       throw std::runtime_error("Fail 1");
    }

    std::string s;
    std::getline(std::cin, s);

    std::map<std::string_view, int> memo;

    for(int loop = 0; loop < q; loop++){
        line.clear();
        std::getline(std::cin, line);
        std::stringstream linestream(std::move(line));

        int l,r, length;
        if (!(linestream >> l >> r)) {
            throw std::runtime_error("Fail 2");
        }

        std::string_view key(&s[l], (r - l + 1));

        auto find = memo.find(key);
        if (find == memo.end()) {
            length = 0;
            for(auto val: key) {
                length += std::islower(val) ? val - 'a' : 0;
            }
            memo[key] = length;
        }
        else {
            length = find->second;
        }
        std::cout << length << "\n";
    }
}

#include <iostream>
#include <string>
#include <sstream>
#include <string_view>
#include <map>

int main()
{
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(NULL);

    std::string line;
    std::getline(std::cin, line);
    std::stringstream linestream(std::move(line));

    int n, q;
    if (!(linestream >> n >> q) {
       throw std::runtime_error("Fail 1");
    }

    std::string s;
    std::getline(std::cin, s);

    std::map<std::string_view, int> memo;

    for(int loop = 0; loop < q; loop++){
        line.clear();
        std::getline(std::cin, line);
        std::stringstream linestream(std::move(line));

        int l,r, length;
        if (!(linestream >> l >> r)) {
            throw std::runtime_error("Fail 2");
        }

        std::string_view key(&s[l], (r - l + 1));

        auto find = memo.find(key);
        if (find == memo.end()) {
            length = 0;
            for(auto val: key) {
                // Not sure about this.
                // Need some unit tests.
                length += std::islower(val) ? val - 'a' + 1: 0;
            }
            memo[key] = length;
        }
        else {
            length = find->second;
        }
        std::cout << length << "\n";
    }
}