Word to elements

w2e.cpp

#include <iostream>
#include <format>
#include <vector>
#include <sstream>
#include <string_view>
#include <set>
#include <map>

extern std::map<std::string_view,std::string_view> elementNames;

const std::set<std::string_view> periodicTable
{
    "h",                                                                                 "he",
    "li","be",                                                  "b", "c", "n", "o", "f", "ne",
    "na","mg",                                                  "al","si","p", "s", "cl","ar",
    "k", "ca","sc","ti","v", "cr","mn","fe","co","ni","cu","zn","ga","ge","as","se","br","kr",
    "rb","sr","y", "zr","nb","mo","tc","ru","rh","pd","ag","cd","in","sn","sb","te","i", "xe",
    "cs","ba",     "hf","ta","w", "re","os","ir","pt","au","hg","tl","pb","bi","po","at","rn",
    "fr","ra",     "rf","db","sg","bh","hs","mt","ds","rg","cn","nh","fl","mc","lv","ts","og",

              "la","ce","pr","nd","pm","sm","eu","gd","tb","dy","ho","er","tm","yb","lu",
              "ac","th","pa","u", "np","pu","am","cm","bk","cf","es","fm","md","no","lr",
};

bool go(std::string_view word, std::vector<std::string_view> &result)
{
    if(word.empty())
    {
        return true;
    }

    for(size_t size : {2,1})
    {
        if(word.size() >= size)
        {
            auto symbol     = word.substr(0,size);

            if(periodicTable.contains(symbol))
            {
                result.push_back(symbol);
        
                auto remainder  = word.substr(size);

                if(go(remainder,result))
                {
                    return true;
                }
                else
                {
                    result.pop_back();
                }
            }
        }
    }

    return false;
}


auto format(auto &result)
{
    std::ostringstream  symbols;
    std::ostringstream  names;

    for(auto const &s : result)
    {
        symbols << s << ' ';
        names   << elementNames[s] << ' ';
    }

    return  std::format("{:30}   {}",symbols.str(), names.str());
}


int main(int argc, char *argv[])
{
    std::vector<std::string_view>  args(argv+1, argv+argc);    
    
    if(!args.empty())
    {
        for(auto word : args)
        {
            std::vector<std::string_view> result;

            std::cout << std::format("{:<20} : ",word);

            if(go(word,result))
            {
                std::cout << format(result);
            }

            std::cout << '\n';
        }
    }
    else
    {
        for(auto [symbol,name] : elementNames)
        {
            std::vector<std::string_view> result;


            if(go(name,result))
            {
                std::cout << std::format("{:<20} : {}\n",name, format(result));
            }

        }
    }
}



std::map<std::string_view,std::string_view> elementNames
{
    {"ac","actinium"},
    {"ag","silver"},
    {"al","aluminium"},
    {"am","americium"},
    {"ar","argon"},
    {"as","arsenic"},
    {"at","astatine"},
    {"au","gold"},
    {"b", "boron"},
    {"ba","barium"},
    {"be","beryllium"},
    {"bh","bohrium"},
    {"bi","bismuth"},
    {"bk","berkelium"},
    {"br","bromine"},
    {"c", "carbon"},
    {"ca","calcium"},
    {"cd","cadmium"},
    {"ce","cerium"},
    {"cf","californium"},
    {"cl","chlorine"},
    {"cm","curium"},
    {"cn","copernicium"},
    {"co","cobalt"},
    {"cr","chromium"},
    {"cs","cesium"},
    {"cu","copper"},
    {"ds","darmstadtium"},
    {"db","dubnium"},
    {"dy","dysprosium"},
    {"er","erbium"},
    {"es","einsteinium"},
    {"eu","europium"},
    {"f", "fluorine"},
    {"fe","iron"},
    {"fl","flerovium"},
    {"fm","fermium"},
    {"fr","francium"},
    {"ga","gallium"},
    {"gd","gadolinium"},
    {"ge","germanium"},
    {"h", "hydrogen"},
    {"he","helium"},
    {"hf","hafnium"},
    {"hg","mercury"},
    {"ho","holmium"},
    {"hs","hassium"},
    {"i", "iodine"},
    {"in","indium"},
    {"ir","iridium"},
    {"k", "potassium"},
    {"kr","krypton"},
    {"la","lanthanum"},
    {"li","lithium"},
    {"lr","lawrencium"},
    {"lu","lutetium"},
    {"lv","livermorium"},
    {"mc","moscovium"},
    {"md","mendelevium"},
    {"mg","magnesium"},
    {"mn","manganese"},
    {"mo","molybdenum"},
    {"mt","meitnerium"},
    {"n", "nitrogen"},
    {"na","sodium"},
    {"nb","niobium"},
    {"nd","neodymium"},
    {"ne","neon"},
    {"nh","nihonium"},
    {"ni","nickel"},
    {"no","nobelium"},
    {"np","neptunium"},
    {"o", "oxygen"},
    {"og","oganesson"},
    {"os","osmium"},
    {"p", "phosphorus"},
    {"pa","protactinium"},
    {"pb","lead"},
    {"pd","palladium"},
    {"pm","promethium"},
    {"po","polonium"},
    {"pr","praseodymium"},
    {"pt","platinum"},
    {"pu","plutonium"},
    {"ra","radium"},
    {"rb","rubidium"},
    {"re","rhenium"},
    {"rf","rutherfordium"},
    {"rg","roentgenium"},
    {"rh","rhodium"},
    {"rh","rhodium"},
    {"rn","radon"},
    {"ru","ruthenium"},
    {"s", "sulphur"},
    {"sb","antimony"},
    {"sc","scandium"},
    {"se","selenium"},
    {"sg","seaborgium"},
    {"si","silicon"},
    {"sm","samarium"},
    {"sn","tin"},
    {"sr","strontium"},
    {"ta","tantalum"},
    {"tb","terbium"},
    {"tc","technetium"},
    {"te","tellurium"},
    {"th","thorium"},
    {"ti","titanium"},
    {"tl","thallium"},
    {"tm","thulium"},
    {"ts","tennessine"},
    {"u", "uranium"},
    {"v", "vanadium"},
    {"w", "tungsten"},
    {"xe","xenon"},
    {"y", "yttrium"},
    {"yb","ytterbium"},
    {"zn","zinc"},
    {"zr","zirconium"},
};


void crossCheck()
{
    for(auto const &element : periodicTable)
    {
        if(!elementNames.contains(element))
        {
            __debugbreak();
        }
    }

    for(auto const&element : elementNames)
    {
        if(!periodicTable.contains(element.first))
        {
            __debugbreak();
        }
    }
}