day 7, "at most" is "less than", not "more than"!

d07/part1.awk

@@ -0,0 +1,16 @@
+BEGIN { LIMIT=100*1000 }
+$2 == "ls" || $1 == "dir" { next}
+$2 == "cd" && $3 == ".." {
+	if (S[depth]<=LIMIT) {
+		R+=S[depth]
+	}
+	S[depth]=0
+	depth -= 1
+}
+$2 == "cd" && $3 != ".." { depth += 1; P[depth]=$3; }
+NF == 2 {
+	for (i=1;i<=depth;i++) {
+		S[i]+=$1
+	}
+}
+END { print R }

d07/print.awk

@@ -0,0 +1,47 @@
+$2 == "ls" || $1 == "dir" { next}
+$2 == "cd" && $3 != ".." {
+	depth += 1
+	l = ""
+	for (i=1;i<depth;i++) {
+		l = l "___ "
+	}
+	print l  $3 "/"
+}
+NF == 2 {
+	l = ""
+	for (i=1;i<=depth;i++) {
+		S[i]+=$1
+		l = l "___ "
+	}
+	print l  $2, "(" $1 ")"
+}
+$2 == "cd" && $3 == ".." {
+	l = ""
+	for (i=1;i<depth;i++) {
+		l = l "___ "
+	}
+	print l "=>", S[depth]
+	S[depth]=0
+	depth -= 1
+}
+
+# part 1
+# awk -f print.awk input | grep -F '=>' | awk 'NF>2 && $(NF)>(100*1000)' | awk '{ print $NF }' | sum0
+
+# part 2
+# TOTAL  70'000'000
+# UPDATE 30'000'000
+# ROOT   43'837'783
+# FREE   26'162'217
+# NEED    3'837'783
+# list all sizes
+# awk -f print.awk input | grep -F '=>' | awk 'NF>2 && $(NF)>(100*1000)' | awk '{ print $NF }' | sort -n
+# find number at the bottom of the list that is >=NEED
+# ...
+# 2882941
+# 3572786
+# 3718312  <= too low
+# 4183246  <= this one
+# 5406295
+# 5928595
+# ...