Compilare: user.cpp: In function ‘int main()’: user.cpp:45:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ^ user.cpp:51:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<x.size();j++) ^ user.cpp:64:22: warning: variable ‘miau’ set but not used [-Wunused-but-set-variable] int ok=1,l=0,miau; ^