Compilare: user.cpp: In function ‘bool solutie(int)’: user.cpp:33:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<v[st[i]].size(); j++) ^ user.cpp: In function ‘void bk(int)’: user.cpp:61:11: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(valid(k)) ^ user.cpp: In function ‘int main()’: user.cpp:92:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] {for(int j=0;j<sol[i].size();j++) ^