Search a list: Difference between revisions

Content added Content deleted
(Added 11l)
m (code cleanup)
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*/
*/
#include <iostream> // std::cout, std::endl
#include <iostream> // std::cout
#include <algorithm> // std::find
#include <algorithm> // std::find
#include <list> // std::list
#include <list> // std::list
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// lambda function with auto typing
// lambda function with auto typing
// auto is easier to write than looking up the compicated
// auto is easier to write than looking up the complicated
// specialized iterator type that is actually returned.
// specialized iterator type that is actually returned.
// Just know that it returns an iterator for the list at the position found,
// Just know that it returns an iterator for the list at the position found,
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auto contains = [](list<string> l, string s) throw(runtime_error)
auto contains = [](list<string> l, string s) throw(runtime_error)
{
{
auto r = find(begin(l), end(l), s );
auto r = find(begin(l), end(l), s );


if ( r == end(l) ) throw runtime_error( s + " not found" );
if( r == end(l) )
throw runtime_error( s + " not found" );


return r;
return r;
};
};


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// name to simplify things.
// name to simplify things.
auto index = [&](list<string> l, string s) noexcept
auto index = [&](list<string> l, string s) noexcept
{
{
vector<int> index_v;
vector<int> index_v;
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int idx = 0;
int idx = 0;


for(auto& r : l)
for(const string& r : l)
{
{
if ( s.compare(r) == 0 ) index_v.push_back(idx); // match -- add to vector
if( s.compare(r) == 0 ) // match -- add to vector
index_v.push_back(idx);
⚫
idx++;
⚫
idx++;
}
}
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// for/in loop
// range-based for loop
// s is a read-only reference, not a copy
for (const string& s : n) // new iteration syntax is simple and intuitive
for (const string& s : n) // new iteration syntax is simple and intuitive
{
{
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auto cont = contains( l , s); // checks if there is any match
auto cont = contains( l , s); // checks if there is any match
if( cont != l.end() ) // found at least one
⚫
vector<int> vf = index( l, s );
{
⚫
vector<int> vf = index( l, s );


cout << "l contains: " << s << " at " ;
cout << "l contains: " << s << " at " ;


for (auto x : vf)
for(auto x : vf) // auto will resolve to int
{ cout << x << " "; } // if vector is empty this doesn't run
{ cout << x << " "; } // if vector is empty this doesn't run


cout << endl ;
cout << "\n";
}


}
}
catch (const runtime_error& r) // string not found
catch (const runtime_error& r) // string not found
{
{
cout << r.what() << endl;
cout << r.what() << "\n";
continue; // try next string
continue; // try next string
}
}

} //for
} //for
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