day 8, wren

d8-wren/main.wren

@@ -0,0 +1,136 @@
+import "aoc" for AoC
+
+class Forest {
+    construct new(w, h) {
+        _w = w
+        _h = h
+        _trees = List.filled(w*h, 0)
+    }
+
+    w { _w }
+    h { _h }
+
+    get(x, y) { _trees[x+_w*y] }
+    set(x, y, t) { _trees[x+_w*y] = t }
+
+    visible_cardinal(x, y) {
+        if(x == 0 || y == 0 || x == w-1 || y == h-1) {
+            return true
+        }
+
+        var t = get(x, y)
+
+        var vis = true
+        for(xi in 0...x) {
+            if(get(xi, y) >= t) {
+                vis = false
+                break
+            }
+        }
+        if(vis) return true
+
+        vis = true
+        for(yi in 0...y) {
+            if(get(x, yi) >= t) {
+                vis = false
+                break
+            }
+        }
+        if(vis) return true
+
+        vis = true
+        for(xi in (x+1)...w) {
+            if(get(xi, y) >= t) {
+                vis = false
+                break
+            }
+        }
+        if(vis) return true
+
+        vis = true
+        for(yi in (y+1)...h) {
+            if(get(x, yi) >= t) {
+                vis = false
+                break
+            }
+        }
+        if(vis) return true
+
+        return false
+    }
+
+    score(x, y) {
+        if(x == 0 || y == 0 || x == w-1 || y == h-1) {
+            return 0
+        }
+
+        var t = get(x, y)
+
+        var score_left = 0
+        for(xi in (x-1)..0) {
+            score_left = score_left + 1
+            if(get(xi, y) >= t) {
+                break
+            }
+        }
+
+        var score_up = 0
+        for(yi in (y-1)..0) {
+            score_up = score_up + 1
+            if(get(x, yi) >= t) {
+                break
+            }
+        }
+
+        var score_right = 0
+        for(xi in (x+1)...(_w)) {
+            score_right = score_right + 1
+            if(get(xi, y) >= t) {
+                break
+            }
+        }
+
+        var score_down = 0
+        for(yi in (y+1)...(_h)) {
+            score_down = score_down + 1
+            if(get(x, yi) >= t) {
+                break
+            }
+        }
+
+        return score_left * score_up * score_right * score_down
+    }
+}
+
+var input = AoC.input
+var row_count = input.where {|x| x == "\n"}.count
+var lines = input.split("\n").where {|x| x != ""}
+
+var forest = null
+var x = 0
+for(line in lines) {
+    if(!forest) forest = Forest.new(line.count, row_count)
+    var y = 0
+    for(tree in line) {
+        forest.set(x, y, Num.fromString(tree))
+        y = y + 1
+    }
+    x = x + 1
+}
+
+var total_visible = 0
+var best_score = 0
+for(x in 0...forest.w) {
+    for(y in 0...forest.h) {
+        if(forest.visible_cardinal(x, y)) {
+            total_visible = total_visible + 1
+        }
+        var score = forest.score(x, y)
+        if(score > best_score) {
+            best_score = score
+        }
+    }
+}
+
+System.print(total_visible)
+System.print(best_score)