Compilare: user.cpp: In function ‘int dfs_color(int)’: user.cpp:50:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:56:13: warning: unused variable ‘i’ [-Wunused-variable] int x,y,i,j; ^ user.cpp:56:15: warning: unused variable ‘j’ [-Wunused-variable] int x,y,i,j; ^ user.cpp:54:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("something.in","r",stdin); ^ user.cpp:55:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("something.out","w",stdout); ^