Compilare: user.cpp: In function ‘int query(int, int)’: user.cpp:58:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int uni(int, int)’: user.cpp:46:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int query(int, int)’: user.cpp:50:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(FOUT,"w",stdout); ^ user.cpp: In function ‘int main()’: user.cpp:62:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(FIN, "r",stdin); ^ user.cpp:63:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(FOUT,"w",stdout); ^ user.cpp:64:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n,&m); ^ user.cpp:67:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x,&y,&code); ^