Day 7

day07.sql

@@ -0,0 +1,71 @@
+with recursive
+
+grid (line, row) as (
+    select
+        unnest(line),
+        generate_subscripts(line, 1) as row
+    from (
+        select string_split(trim(content, e'\n'), e'\n') as line
+        from read_text('data/07.in')
+    )
+),
+
+dims as (
+    select
+        max(row) as height,
+        max(length(line)) as width
+    from grid
+),
+
+initial as (
+    select col from range(1, (select width from dims)) r (col), grid
+    where row = 1 and line[col] <> '.'
+),
+
+trace (depth, col, num) as (
+    select
+        1,
+        col,
+        cast(1 as int128)
+    from initial
+
+    union
+
+    select
+        depth,
+        col,
+        sum(num)
+    from
+        (
+            select
+                depth + 1 as depth,
+                unnest(
+                    case
+                        when line[col] = '^'
+                            then [col - 1, col + 1]
+                        else [col]
+                    end
+                ) as col,
+                num
+            from
+                trace, grid
+            where
+                depth + 1 = row
+        )
+    group by depth, col
+),
+
+part1 (solution) as (
+    select count(*) from trace, grid
+    where line[col] = '^' and depth + 1 = row
+),
+
+part2 (solution) as (
+    select sum(num) from trace
+    where depth = (select height from dims)
+)
+
+select
+    part1.solution as p1,
+    part2.solution as p2
+from part1, part2;