Eroare de compilare: main.cpp: In function 'int main()': main.cpp:33:23: error: 'ch' was not declared in this scope else s.push( {ch, i} ); ^~ main.cpp:33:30: error: no matching function for call to 'std::stack<el>::push(<brace-enclosed initializer list>)' else s.push( {ch, i} ); ^ In file included from /usr/include/c++/6/stack:61:0, from main.cpp:3: /usr/include/c++/6/bits/stl_stack.h:218:7: note: candidate: void std::stack<_Tp, _Sequence>::push(const value_type&) [with _Tp = el; _Sequence = std::deque<el, std::allocator<el> >; std::stack<_Tp, _Sequence>::value_type = el] push(const value_type& __x) ^~~~ /usr/include/c++/6/bits/stl_stack.h:218:7: note: no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'const value_type& {aka const el&}' /usr/include/c++/6/bits/stl_stack.h:223:7: note: candidate: void std::stack<_Tp, _Sequence>::push(std::stack<_Tp, _Sequence>::value_type&&) [with _Tp = el; _Sequence = std::deque<el, std::allocator<el> >; std::stack<_Tp, _Sequence>::value_type = el] push(value_type&& __x) ^~~~ /usr/include/c++/6/bits/stl_stack.h:223:7: note: no known conversion for argument 1 from '<brace-enclosed initializer list>' to 'std::stack<el>::value_type&& {aka el&&}' Non zero exit status: 1