Compilare: user.cpp: In function ‘int main()’: user.cpp:16:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<s.size(); ++i) ^ user.cpp:22:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=i; j<=(s.size()-1-i)/2+i; ++j) ^ user.cpp:31:9: warning: ‘ok’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(ok==1) break; ^