Compilare: user.cpp: In function ‘void trans(int)’: user.cpp:17:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j+1>=k.size() || (k[j-1]!=k[j] && j)) j--; ~~~^~~~~~~~~~ user.cpp:18:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j+2<k.size() && k[j]==k[j+1]) j++; ~~~^~~~~~~~~