Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:57:45: warning: statement has no effect [-Wunused-value] eprintf("child of %d, %d\n",u,v); ^ user.cpp: In function ‘int main()’: user.cpp:103:43: warning: statement has no effect [-Wunused-value] eprintf("ans[%d] = %d\n",i,ans[i]); ^ user.cpp: In function ‘int read()’: user.cpp:41:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] inline int read(){int x;scanf(" %d",&x);return x;} ^