/*************************************** Programmed by: __ __ ___ _ _ _ __ _ ®© | \ / |/ \| |_| | / \ | \ | | | |\V/| | O | _ |/ Δ \| |\\| | |_| V |_|\___/|_| |_|_/ \_|_| \__| To do sorting in diffrent ways. ***************************************/ #include using namespace std; template class Vec { /* class to keep a vector & to have sort functions */ vector v; public: Vec(initializer_list il): v(il) {} auto sort(bool reverse = false) { if (reverse) ::sort( begin(v), end(v), greater() ); else ::sort(begin(v), end(v)); return *this; } auto sort_by( auto func, bool reverse = false ) { if (reverse) { ::sort(begin(v), end(v), func); ::reverse(begin(v), end(v)); } else ::sort(begin(v), end(v), func); return *this; } string to_string() { stringstream sout; sout << "[ "; for ( auto i = begin(v); i < end(v); i++ ) { if (typeid(*i)==typeid(string)) sout << "\"" << *i << "\""; else sout << *i; if (i != (end(v) - 1)) sout << ", "; } sout << " ]\n"; return sout.str(); } }; int main() { Vec v = {5, 7, 8, 2, 4}; // ⬇️ simple sorting cout << v.sort().to_string(); // reverse sorting⬇️ cout << v.sort(/* reverse = */ true) .to_string(); Vec l = {"Swift", "Python", "Go", "C++", "R", "Lisp"}; // lambda comparing string sizes auto compare_size = [] ( string s1, string s2 ) { return size(s1) < size(s2); }; // sorting acc to ⬇️string size cout << l .sort_by(/* func = */ compare_size) .to_string(); cout<< l.sort().to_string(); // ⬆️simple sorting(A-Z) // some lambda: f(x) = x² - 2x auto f = [] (int x) { return x*x - 2*x; }; // lambda comparing 2 integer values // using lambda f() auto compare_result = [f] ( int i1, int i2 ) { return f(i1) < f(i2); }; Vec n = {0, 1, 2, 3, -2}; // sorting according to ⬇️function n.sort_by( /* func = */ compare_result, /* reverse = */ true ); // and then reversed⬆️ cout << n.to_string(); }

Different ways of sorting