Solution to Robot Journey in TSQL https://github.com/mikehadlow/Journeys

solution.sql

declare @input nvarchar(max) = 
N'1 1 E
RFRFRFRF
1 1 E

3 2 N
FRRFLLFFRRFLL
3 3 N

0 3 W
LLFFFLFLFL
2 4 S';

declare @journeys as table (id int, startpos nvarchar(max), endpos nvarchar(max), instructions nvarchar(max));

-- Phase 1: Parsing the string

with tmp as (
    select j as txt, ROW_NUMBER() OVER(order by (select 1)) as [rn]
    from STRING_SPLIT(@input, CHAR(13)) cross apply (SELECT REPLACE(REPLACE(value, CHAR(13), ''), CHAR(10), '') as j) b
    where j <> ''
)
insert into @journeys(id, startpos, endpos, instructions)
select ROW_NUMBER() OVER(order by start_pos.rn) as id, trim(start_pos.txt), trim(end_pos.txt), trim(instrs.txt)
from (select * from tmp where rn % 3 = 1) as start_pos
outer apply (select * from tmp tmp2 where rn % 3 = 2 and tmp2.rn = start_pos.rn + 1) instrs
outer apply (select * from tmp tmp2 where rn % 3 = 0 and tmp2.rn = start_pos.rn + 2) end_pos

declare @journey_steps as table (journey_id int, n int, x int, y int, dir char(1));

insert into @journey_steps(journey_id, n, x, y, dir)
select id, 0 as n,
    CAST(SUBSTRING (j, 1, 1) as int), 
    CAST(SUBSTRING (j, 2, 1) as int), 
    SUBSTRING (j, 3, 1)
from @journeys a cross apply (select trim(replace(startpos, ' ', '')) as j) b

-- Phase 2: Lookup tables used in solution

declare @directions as table (n int identity(0,1), dir char(1));
insert into @directions(dir) values ('N'), ('E'), ('S'), ('W');

declare @forward_offsets as table (dir char(1), x int , y int);
insert into @forward_offsets values ('N', 0, 1), ('E', 1, 0), ('S', 0, -1), ('W', -1, 0);

-- Phase 3: Solution via recursive CTE

with steps as (
    select journey_id, n, x, y, dir, CAST('' as nvarchar(max)) as instr_applied
    from @journey_steps b

    union all
    
    select prev.journey_id, prev.n + 1, isnull(new_x, prev.x), isnull(new_y, prev.y), isnull(new_dir, prev.dir), cur_instr
    from steps prev
    join @journeys j on j.id = prev.journey_id
    join @directions prev_dir on prev.dir = prev_dir.dir
    cross apply (
        select SUBSTRING(j.instructions, prev.n + 1, 1) as cur_instr
    ) instr
    outer apply (
        select new_x, new_y
        from (select x, y from @forward_offsets o where cur_instr = 'F' and o.dir = prev.dir) o
        cross apply (select prev.x + o.x as new_x, prev.y + o.y as new_y) n
    ) new_pos
    outer apply (
        select d.dir as new_dir
        from (select case cur_instr when 'R' then 1 when 'L' then -1 end as dir_incr) a
        join @directions d on d.n % 4 = (prev_dir.n + dir_incr + 4) % 4 -- Note: the +4 is to ensure it wraps properly with negative increments
    ) new_dir
    where prev.n <= len(instructions)
)
select journey_id, n as step_number, x, y, dir, instr_applied, j.startpos, j.endpos as expected_end
from steps s
join @journeys j on j.id = s.journey_id
order by journey_id, n

the_output.csv