Compilare: main.cpp: In function 'int main()': main.cpp:40:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<elem.size();i++) ~^~~~~~~~~~~~ main.cpp:49:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<elem.size();i++) ~^~~~~~~~~~~~ main.cpp:62:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<elem.size();i++) ~^~~~~~~~~~~~ main.cpp:76:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<elem.size();i++) ~^~~~~~~~~~~~ main.cpp:89:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<elem.size();i++) ~^~~~~~~~~~~~ main.cpp:103:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<elem.size();i++) ~^~~~~~~~~~~~ main.cpp:116:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<elem.size();i++) ~^~~~~~~~~~~~ main.cpp:130:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<elem.size();i++) ~^~~~~~~~~~~~ main.cpp:143:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<elem.size();i++) ~^~~~~~~~~~~~