day 10, part 2, no need to buffer, spare 6 loc

d10/part2.awk

@@ -1,20 +1,14 @@
-BEGIN { x=1 }
 function inc() {
-  i = (c%40)
-	A[c+1] = (i==x-1||i==x||i==x+1) ? "█" : "░"
-	c+=1
+	i = (c%40)
+	r = r ((i==x||i==x+1||i==x+2) ? "█" : " ")
+	if (i == 39) {
+		print r
+		r = ""
+	}
+	c++
 }
 { inc() }
 $1 == "addx" {
 	inc()
 	x+=$2
 }
-END {
-	for (i=0;i<=5;i++) {
-		r = ""
-		for (j=1;j<=40;j++) {
-			r = r A[i*40+j]
-		}
-		print r
-	}
-}