substring

-module(solution).
-export([main/0]).

main() ->
    {ok,[Count]}=io:fread("","~d"),
    main(Count,[]).

main(0,Acc) ->
    lists:foreach(fun(Elem) ->  io:format("~s~n",[Elem]) end,lists:reverse(Acc));

main(Count,Acc) ->
    {ok,[Str,SubStr]}=io:fread("","~s~s"),
    Table=create_table(SubStr,dict:new(),string:len(SubStr)-2),
    io:format("Table~p~n",[dict:to_list(Table)]),
    Res=find_str(Table,Str,SubStr),
    main(Count-1, [Res|Acc]).


create_table(Str,Acc,Len) ->
    Check=string:slice(Str,1),
    if Check /= "" ->
        create_table(string:slice(Str,1),dict:store(string:slice(Str,1,1),Len,Acc),Len-1);
       Check == "" -> Acc end.

find_str(_,"",SubStr) -> "NO";

find_str(Table,Str,SubStr) ->
    Len=string:len(SubStr),
    LenStr=string:len(Str),
    if Len>LenStr -> "NO";
    Len=<LenStr ->
    LastSymbStr=string:sub_string(Str,Len,Len),
    LastSymbSub=string:sub_string(SubStr,Len,Len),
    io:format("sravnenie ~p s ~p~n",[LastSymbStr,LastSymbSub]),
    CharsEq=string:equal(LastSymbStr,LastSymbSub),
    if CharsEq==false ->
        case dict:find(LastSymbStr,Table) of
        error -> find_str(Table, string:slice(Str,1),SubStr);
        {ok,B} -> io:format("offset to ~p~n", [B]),
            find_str(Table,string:slice(Str,B),SubStr)
        end;
       true -> Eq=equal_str(string:sub_string(Str,1,Len),SubStr),
           if Eq ==true -> "YES";
        true -> find_str(Table, string:slice(Str,1),SubStr) end
        end
    end .
equal_str([],[]) -> true;
equal_str([_],[]) -> true;
equal_str([A|S1],[B|S2]) ->
    if A==B ->
        equal_str(S1,S2);
       A/=B -> false
    end.