Compilare: main.cpp:7:24: warning: integer overflow in expression [-Woverflow] const int inf = (1<<31)-1; ~~~~~~~^~ main.cpp: In member function 'bool compare::operator()(int, int)': main.cpp:16:17: warning: statement has no effect [-Wunused-value] dist[x] > dist[y]; ~~~~~~~~^~~~~~~~~ main.cpp:17:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^