Compilare: user.cpp: In function ‘void preproc(std::string, int)’: user.cpp:21:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<=z.size(); ++i) b[i]=z[i-1]; ^ user.cpp:22:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<=v.size(); ++i) s[i]=v[i-1]; ^ user.cpp: In function ‘int main()’: user.cpp:53:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<=tx.size(); ++i) bst[i]=(1<<30); ^ user.cpp:54:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<=tx.size(); ++i) { ^