Compilare: user.cpp: In function ‘int main()’: user.cpp:15:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<line.size();i++) ^ user.cpp:38:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<newline.size() ;j++) ^ user.cpp:45:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=j+1;k<newline.size();k++) ^