Compilare: user.cpp: In function ‘int main()’: user.cpp:28:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(n1.size() == sz){ ~~~~~~~~~~^~~~~ user.cpp:33:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] }else if (n2.size() == sz){ ~~~~~~~~~~^~~~~ user.cpp:46:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < n0.size(); ++i) ~~^~~~~~~~~~~ user.cpp:63:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(n1.size() == sz){ ~~~~~~~~~~^~~~~ user.cpp:69:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(p < max(n2.size(), n3.size())){ ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~ user.cpp:74:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(p < n1.size()){ ~~^~~~~~~~~~~ user.cpp:85:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] }else if (n2.size() == sz){ ~~~~~~~~~~^~~~~ user.cpp:91:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(p < max(n1.size(), n3.size())){ ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~ user.cpp:96:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(p < n2.size()){ ~~^~~~~~~~~~~ user.cpp:109:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(p < max(n1.size(), n2.size())){ ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~ user.cpp:114:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(p < n3.size()){ ~~^~~~~~~~~~~