https://www.hackerrank.com/challenges/30-2d-arrays

Erlang

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

main() ->

    Arr = read_2darray(6,6,"~d"),
    io:format("~w~n",[lists:max(groupSum(Arr,1,1,[]))]).

%taken in reverse order
read_array(0,_) -> [];
read_array(N,D) -> 
   {ok, [X]} = io:fread("", D),
   [X | read_array(N-1,D)].

read_2darray(0,_,_) -> [];
read_2darray(N,M,D) ->
   Q=read_array(M,D),
   [Q | read_2darray(N-1,M,D)].

%done in order fashion
groupSum([],_,_,Res) -> Res;
groupSum(_,R,_,Res) when (R > 4)  -> Res;
groupSum(Arr,R,C,Res) when (C > 4)  -> groupSum(Arr,R+1,1,Res);
groupSum(Arr,R,C,Res) -> V = sum(Arr,[{R,C},{R,C+1},{R,C+2},{R+1,C+1},{R+2,C},{R+2,C+1},{R+2,C+2}],0),
                         groupSum(Arr,R,C+1,[V|Res]).

sum(_,[],SumRes) -> SumRes;
%first get row than get column in the given row
sum(Arr,[{A,B}|Xs],SumRes) -> sum(Arr,Xs,lists:nth(B,lists:nth(A,Arr))+SumRes).