Compilare: main.cpp: In function 'std::__cxx11::string inmultirea(std::__cxx11::string, std::__cxx11::string)': main.cpp:13:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s1.size(); i++) { ~~^~~~~~~~~~~ main.cpp:14:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < s2.size(); j++) { ~~^~~~~~~~~~~ main.cpp:21:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v3.size()-1; i++) { ~~^~~~~~~~~~~~~ main.cpp:31:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i= 0; i < v3.size(); i++) { ~~^~~~~~~~~~~