Compilare: user.cpp: In function ‘int check()’: user.cpp:57:7: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(l==3) ^ user.cpp: In function ‘int check_B()’: user.cpp:25:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int check_C()’: user.cpp:49:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int check()’: user.cpp:85:1: warning: control reaches end of non-void function [-Wreturn-type] } ^