chore: fix tests for day 4 & 5

day04/main_test.go

@@ -17,16 +17,18 @@ func TestExample(t *testing.T) {
 	is := is.New(t)
 	scan := bufio.NewScanner(bytes.NewReader(example))
 
-	points, cards := run(scan)
-	is.Equal(points, 13)
-	is.Equal(cards, 30)
+	r, err := run(scan)
+	is.NoErr(err)
+	is.Equal(r.points, 13)
+	is.Equal(r.cards, 30)
 }
 
 func TestSolution(t *testing.T) {
 	is := is.New(t)
 	scan := bufio.NewScanner(bytes.NewReader(input))
 
-	points, cards := run(scan)
-	is.Equal(points, 23235)
-	is.Equal(cards, 5920640)
+	r, err := run(scan)
+	is.NoErr(err)
+	is.Equal(r.points, 23235)
+	is.Equal(r.cards, 5920640)
 }

day05/main_test.go

@@ -20,19 +20,20 @@ func TestExample(t *testing.T) {
 	is := is.New(t)
 	scan := bufio.NewScanner(bytes.NewReader(example))
 
-	minLocation, minRangeLocation := run(scan)
-	is.Equal(minLocation, 35)
-	is.Equal(minRangeLocation, 46)
+	r, err := run(scan)
+	is.NoErr(err)
+	is.Equal(r.minLocation, 35)
+	is.Equal(r.minRange, 46)
 }
 
 func SkipTestSolution(t *testing.T) {
 	is := is.New(t)
 	scan := bufio.NewScanner(bytes.NewReader(input))
 
-	minLocation, minRangeLocation := run(scan)
-	is.Equal(minLocation, 199602917)
-	is.Equal(minRangeLocation, 0)
-
+	r, err := run(scan)
+	is.NoErr(err)
+	is.Equal(r.minLocation, 199602917)
+	is.Equal(r.minRange, 0)
 }
 
 func TestLookup(t *testing.T) {

day12/main.go

@@ -23,6 +23,7 @@ func (r result) String() string { return fmt.Sprintf("%#v", r) }
 
 func run(scan *bufio.Scanner) (*result, error) {
 	var matches []int
+	var matches2 []int
 
 	for scan.Scan() {
 		text := scan.Text()
@@ -31,16 +32,24 @@ func run(scan *bufio.Scanner) (*result, error) {
 			continue
 		}
 
+		// part 1 - brute force
 		grouping := aoc.SliceMap(aoc.Atoi, strings.Split(text, ",")...)
 		pattern := []rune(status)
-		missing := countQuestion(pattern)
+		// sp := spring{pattern: pattern, grouping: grouping, missingNo: countQuestion(pattern)}
+		// matches = append(matches, sp.findMatches())
+		matches = append(matches, countPossible(pattern, grouping))
 
-		s := spring{pattern: pattern, grouping: grouping, missingNo: missing}
-
-		matches = append(matches, s.findMatches())
+		// part 2 - NFA
+		b, a := status, text
+		bn, an := "", ""
+		for i := 0; i < 5; i++ {
+			bn, an = bn+b+"?", an+a+","
+		}
+		b, a = strings.TrimSuffix(bn, "?"), strings.TrimSuffix(an, ",")
+		matches2 = append(matches2, countPossible([]rune(b), aoc.SliceMap(aoc.Atoi, strings.Split(a, ",")...)))
 	}
 
-	return &result{valuePT1: aoc.Sum(matches...)}, nil
+	return &result{valuePT1: aoc.Sum(matches...), valuePT2: aoc.Sum(matches2...)}, nil
 }
 
 type spring struct {
@@ -89,6 +98,63 @@ func (s *spring) genPatterns() []string {
 
 	return lis
 }
+func countPossible(s []rune, c []int) int {
+	pos := 0
+
+	cstates := map[state]int{{}: 1} // current state
+	nstates := map[state]int{}      // next state
+
+	for len(cstates) > 0 {
+		for st, num := range cstates {
+			si, ci, cc, expdot := st.springIndex, st.groupIndex, st.continuous, st.expectDot
+			
+			// have we reached the end?
+			if si == len(s) {
+				if ci == len(c) {
+					pos += num
+				}
+				continue
+			}
+
+			switch {
+			case (s[si] == '#' || s[si] == '?') && ci < len(c) && !expdot:
+				// we are still looking for broken springs
+				if s[si] == '?' && cc == 0 {
+					// we are not in a run of broken springs, so ? can be working
+					nstates[state{si + 1, ci, cc, expdot}] += num
+				}
+
+				cc++
+
+				if cc == c[ci] {
+					// we've found the full next contiguous section of broken springs
+					ci++
+					cc = 0
+					expdot = true // we only want a working spring next
+				}
+
+				nstates[state{si + 1, ci, cc, expdot}] += num
+
+			case (s[si] == '.' || s[si] == '?') && cc == 0:
+				// we are not in a contiguous run of broken springs
+				expdot = false
+				nstates[state{si + 1, ci, cc, expdot}] += num
+			}
+		}
+
+		// swap and clear previous states
+		cstates, nstates = nstates, cstates
+		clear(nstates)
+	}
+	return pos
+}
+
+type state struct {
+	springIndex int
+	groupIndex  int
+	continuous  int
+	expectDot   bool
+}
 
 func countQuestion(pattern []rune) int {
 	count := 0
@@ -119,4 +185,3 @@ func countGroupings(pattern []rune) []int {
 	}
 	return groupings
 }
-

day12/main_test.go

@@ -27,7 +27,7 @@ func TestExample(t *testing.T) {
 
 	t.Log(result)
 	is.Equal(result.valuePT1, 21)
-	is.Equal(result.valuePT2, 0)
+	is.Equal(result.valuePT2, 525152)
 }
 
 func TestSolution(t *testing.T) {
@@ -39,7 +39,7 @@ func TestSolution(t *testing.T) {
 
 	t.Log(result)
 	is.Equal(result.valuePT1, 8193)
-	is.Equal(result.valuePT2, 0)
+	is.Equal(result.valuePT2, 45322533163795)
 }
 
 func TestPower2(t *testing.T) {