Compilare: user.cpp: In function ‘int dfs_color(int)’: user.cpp:47:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:53:15: warning: unused variable ‘j’ [-Wunused-variable] int x,y,i,j; ^ user.cpp:51:38: 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:52:40: 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); ^ user.cpp:66:22: warning: ‘i’ may be used uninitialized in this function [-Wmaybe-uninitialized] cout<<t[i]; ^