Compilare: user.cpp: In function ‘int build(int, int)’: user.cpp:59:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int insertion(int, int, int)’: user.cpp:62:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (node < arb.size()) { ^ user.cpp:71:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int interval(int, int, int)’: user.cpp:76:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (node < arb.size()) { ^ user.cpp:85:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int up(int)’: user.cpp:92:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int change(int, int, int)’: user.cpp:107:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^