note
    description: "Summary description for {CIPHER}."
    author: ""
    date: "$Date$"
    revision: "$Revision$"

class
    CIPHER

feature

    arr: ARRAY2[CHARACTER]

    k_str(k, tx: STRING): STRING
    local
        i: INTEGER
        j: INTEGER
        new_k: STRING
    do
        from
            i := 1
            j := 0
            new_k := ""
        until
            i = tx.count+1
        loop
            if(tx.item (i).code > 64 and tx.item (i).code < 91) then
                new_k.append_character (k.item (j \\ k.count + 1))
                j := j + 1
            else
                new_k.append_character (tx.item (i))
            end
            i := i + 1
        end
        Result := new_k

    end

    decrypt(k, tx: STRING): STRING
    local
        i: INTEGER
        new_str: STRING
    do
        from
            i := 1
            new_str := ""
        until
            i = tx.count+1
        loop
            if(tx.item (i).code > 64 and tx.item (i).code < 91 and k.item (i).code > 64 and k.item (i).code < 91) then
                new_str.append_character((((tx.item (i).code + k.item (i).code - (65*2))\\26) + 65).to_character)
            else
                new_str.append_character (tx.item (i))
            end
            i := i + 1
        end
        Result := new_str

    end

    box(str: STRING): STRING
    local

        exp: BOOLEAN
        i: INTEGER
        j: INTEGER
        k: INTEGER
        z: INTEGER
        str1: STRING
        x: INTEGER
        times: INTEGER
        q: INTEGER
    do
        str1 := ""
        x := 0
        times := 1
        from
            i := 1
            exp := true
        until
            exp = false
        loop
            if(i*i <= str.count) then
                i := i + 1
            else
                exp := false
            end
        end

        create arr.make_filled ('*', i, i)
        from
            j := 1
            z := 1
        until
            j > i
        loop
            from
                k := 1
            until
                k > i
            loop
                if((z > str.count) = false) then
                    arr.put (str.item (z), j, k)

                end
                k := k + 1
                z := z + 1
            end
            j := j + 1

        end


        from k:=1
        until k>i
        loop
            from j:=1
            until j>i
            loop
                print (arr.item (k, j)) print (" ")
                j:=j+1
            end
            k:=k+1
            print("%N")
        end

        from k:=i
        until k<I//2
        loop
            str1.append_string (getRightColumn(k,i-k+1,i))

            str1.append_string (getBottomRow(k,i-k+2,i))

            str1.append_string (getLeftColumn(k,i-k+2,i))

            str1.append_string (getTopRow(k,i-k+2,i))

            k:=k-1
        end


        Result := str1
    end

    getRightColumn(startind, endind, maxind: INTEGER):STRING
    local
        strres: STRING
        j: INTEGER
    do
        strres:=""
        from j:=startind
        until j<endind
        loop
            if (arr.item(maxind-j+1, startind)/~'*') then
                strres.append_character(arr.item (maxind-j+1, startind))
            end
            j:=j-1
        end
        RESULT:= strres

    end

    getBottomRow(startind, endind, maxind: INTEGER):STRING
    local
        strres: STRING
        j: INTEGER
    do
        strres:=""
        from j:=startind
        until j<endind
        loop
            if (arr.item(startind, j)/~'*') then
                strres.append_character(arr.item (startind, j))
            end
            j:=j-1
        end
        RESULT:= strres

    end

    getLeftColumn(startind, endind, maxind: INTEGER):STRING
    local
        strres: STRING
        j: INTEGER
    do
        strres:=""
        from j:=startind
        until j<endind
        loop
            if (arr.item(j , maxind-startind+1)/~'*') then
                strres.append_character(arr.item (j, maxind-startind+1))
            end
            j:=j-1
        end
        RESULT:= strres

    end

    getTopRow(startind, endind, maxind: INTEGER):STRING
    local
        strres: STRING
        j: INTEGER
    do
        strres:=""
        from j:=startind
        until j<endind
        loop
            if (arr.item(maxind-startind+1, maxind-j+1)/~'*') then
                strres.append_character(arr.item (maxind-startind+1, maxind-j+1))
            end
            j:=j-1
        end
        RESULT:= strres

    end


end