erlang:猜數字

-module(test). 
-export([f/1]). 
  
f(N)-> 
    if
        50 == N -> 
                io:format("find!~n~-5s:~-5s~n",[integer_to_list(1),integer_to_list(50)]); 
        true-> 
                f2(N,1,100,1) 
end. 

f2(N,S,E,T)  -> 
if
  
trunc((S+E)/2)>N-> 
io:format("~-5w:~-5w~n",[T,trunc((S+E)/2)]), 
f2(N,S,trunc((S+E)/2),T+1); 
  
trunc((S+E)/2)<N-> 
io:format("~-5w:~-5w~n",[T,trunc((S+E)/2)]), 
f2(N,trunc((S+E)/2),E,T+1); 
  
true-> 
io:format("find!~n~-5w:~-5w~n",[T,N]) 
  
end. 

1-100之間的猜數，輸出猜數過程