Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:11:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[k].size();i++){ ^ user.cpp:14:5: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(OK==1) ^ user.cpp: In function ‘int main()’: user.cpp:32:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&T); ^ user.cpp:35:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&n); ^ user.cpp:37:36: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&x,&y); ^