Compilare: user.cpp: In function ‘int _find(int)’: user.cpp:19:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < v[poz].size() ; i++) if(v[poz][i] == value) return i; ^ user.cpp: In function ‘int main()’: user.cpp:43:11: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(op == 3) ^