Compilare: main.cpp: In function 'void shuntingYard(int, std::__cxx11::string)': main.cpp:22:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < s.length(); i++) { ~~^~~~~~~~~~~~ main.cpp: In function 'void citire()': main.cpp:52:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 2; i < s.length(); i++) ~~^~~~~~~~~~~~ main.cpp:57:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 4; i < s.length(); i++) { ~~^~~~~~~~~~~~ main.cpp: In function 'long long int calcExpresie(std::__cxx11::string, int*)': main.cpp:71:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < pol.length(); i++) { ~~^~~~~~~~~~~~~~ main.cpp: In function 'long long int parcurgeFunctie(int, int&)': main.cpp:96:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (; i < exp.length(); i++) ~~^~~~~~~~~~~~~~ main.cpp:105:1: warning: control reaches end of non-void function [-Wreturn-type] } ^