Compilare: user.cpp: In function ‘void df(int)’: user.cpp:15:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<h[n].size();++i) ^ user.cpp:21:26: warning: suggest parentheses around comparison in operand of ‘^’ [-Wparentheses] if (sol[n]^sol[x]==bit) continue; ^ user.cpp:20:12: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if (ma[x]) ^ user.cpp: In function ‘int main()’: user.cpp:74:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0;j<h[i].size();++j) ^