Compilare: main.cpp: In function 'int main()': main.cpp:54:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 54 | for (int i = 0; i < input.size(); i++) { | ~~^~~~~~~~~~~~~~ main.cpp:66:92: warning: comparison of integer expressions of different signedness: 'std::stack<int>::size_type' {aka 'long unsigned int'} and '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} [-Wsign-compare] 66 | if (priority[input[i]] < priority[operations.top()] && calculations.size() == depth.top()) { | ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~ main.cpp:75:119: warning: comparison of integer expressions of different signedness: 'std::stack<int>::size_type' {aka 'long unsigned int'} and '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} [-Wsign-compare] 75 | if (priority[input[i]] > priority[operations.top()] && calculations.size() > 1 && calculations.size() == depth.top()) { | ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~ main.cpp:86:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 86 | if (i + 1 != input.size()) { | ~~~~~~^~~~~~~~~~~~~~~ main.cpp:88:105: warning: comparison of integer expressions of different signedness: 'std::stack<int>::size_type' {aka 'long unsigned int'} and '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} [-Wsign-compare] 88 | if (priority[input[i + 1]] >= priority[operations.top()] && calculations.size() - 1 == depth.top()) | ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~