day 11, parts 1 & 2, cleaner

11/11_new.awk

@@ -0,0 +1,41 @@
+BEGIN { FS = "" }
+
+{ for(i=1;i<=NF;i++) o[NR,i] = $i }
+
+END{
+	s=1
+	while(nflashes!=NF*NR){
+		nflashes = 0
+		delete visited
+		for(i in o) o[i]++
+
+		do{
+			for(y=1;y<=NR;y++){
+				for(x=1;x<=NF;x++){
+					if(!visited[y,x] && o[y,x]>9){
+						if(y>1 && x>1) o[y-1,x-1]++
+						if(y>1 && x<NF) o[y-1,x+1]++
+						if(y>1) o[y-1,x]++
+						if(x>1) o[y,x-1]++
+						if(x<NF) o[y,x+1]++
+						if(y<NR && x>1) o[y+1,x-1]++
+						if(y<NR && x<NF) o[y+1,x+1]++
+						if(y<NR) o[y+1,x]++
+						visited[y,x] = 1
+					}
+				}
+			}
+			tochange=0
+			for(i in o) tochange+=(o[i]>9) && !visited[i]
+
+		} while(tochange)
+
+		for(i in o ){
+			if( o[i]>9 ){ o[i] = 0; nflashes++ }
+		}
+		flashes += nflashes
+		if(s==100) print "part 1:", flashes
+		s++
+	}
+	print "part 2: step", s-1
+}