mirror of
https://github.com/RussellChamp/advent-of-code-2021.git
synced 2026-10-27 21:52:32 +00:00
better try
This commit is contained in:
RussellChamp committed
1 parent
0b5bf004f7
commit
514344b8d1
2 files changed
+208
-174
No files matched your search
+126
-142
@@ -7,6 +7,7 @@ import (
|
||||
"AoC2021/utils/timer"
|
||||
"bufio"
|
||||
"fmt"
|
||||
"math"
|
||||
"os"
|
||||
"strconv"
|
||||
)
|
||||
@@ -54,18 +55,16 @@ func part1() {
|
||||
|
||||
for scanner.Scan() {
|
||||
line := scanner.Text()
|
||||
log.Printf(log.DEBUG, "Line #%3d: ", lines+1)
|
||||
if lines == 0 {
|
||||
log.Printf(log.DEBUG, "%s\n", line)
|
||||
s = ParseSnumStr(line)
|
||||
} else {
|
||||
log.Printf(log.DEBUG, "+ %s\n", line)
|
||||
s = AddSnum(s, ParseSnumStr(line))
|
||||
log.Printf(log.DEBUG, "%10s = %s\n", "", s.ToString())
|
||||
}
|
||||
|
||||
// fmt.Printf("SNum #%d: %s\n", lines+1, s.ToString())
|
||||
|
||||
lines++
|
||||
if lines > 1 {
|
||||
break
|
||||
}
|
||||
}
|
||||
|
||||
log.Printf(log.NORMAL, "Read %d lines from input\n", lines)
|
||||
@@ -79,50 +78,27 @@ func part2() {
|
||||
log.Println(log.NORMAL, " Answer: ")
|
||||
}
|
||||
|
||||
type Direction int
|
||||
// Snailfish number
|
||||
type Snum []int
|
||||
|
||||
const (
|
||||
LEFT Direction = 0
|
||||
RIGHT Direction = 1
|
||||
UP Direction = 2
|
||||
LBracket int = -1
|
||||
RBracket int = -2
|
||||
Comma int = -3
|
||||
)
|
||||
|
||||
// Snailfish number
|
||||
// consists of a pair of numbers
|
||||
// the "left" and "right" side can consist of EITHER a normal value or another pair
|
||||
type Snum struct {
|
||||
lVal int
|
||||
rVal int
|
||||
lPtr *Snum
|
||||
rPtr *Snum
|
||||
parentPtr *Snum
|
||||
dir Direction
|
||||
}
|
||||
|
||||
func ParseSnumStr(line string) Snum {
|
||||
var s Snum
|
||||
var sPtr = &s
|
||||
log.Printf(log.DIAGNOSTIC, "Starting to parse snum line \"%s\"\n", line)
|
||||
|
||||
// start on idx 1 and skip the initial open bracket
|
||||
for idx := 1; idx < len(line); idx++ {
|
||||
for idx := 0; idx < len(line); idx++ {
|
||||
switch line[idx] {
|
||||
case '[':
|
||||
if sPtr.dir == LEFT {
|
||||
// create a new snum on the left side
|
||||
sPtr.lPtr = &Snum{parentPtr: sPtr}
|
||||
sPtr.dir = RIGHT
|
||||
sPtr = sPtr.lPtr
|
||||
} else {
|
||||
sPtr.rPtr = &Snum{parentPtr: sPtr}
|
||||
sPtr = sPtr.rPtr
|
||||
}
|
||||
s = append(s, LBracket)
|
||||
case ']':
|
||||
// go up a level
|
||||
sPtr.dir = LEFT
|
||||
sPtr = sPtr.parentPtr
|
||||
s = append(s, RBracket)
|
||||
case ',':
|
||||
continue
|
||||
s = append(s, Comma)
|
||||
default:
|
||||
// if it's not a bracket or a comma then it must be a number
|
||||
endIdx := idx + 1
|
||||
@@ -132,15 +108,9 @@ func ParseSnumStr(line string) Snum {
|
||||
strVal := line[idx:endIdx]
|
||||
iVal, err := strconv.Atoi(strVal)
|
||||
check(err)
|
||||
s = append(s, iVal)
|
||||
|
||||
if sPtr.dir == LEFT {
|
||||
sPtr.lVal = iVal
|
||||
sPtr.dir = RIGHT
|
||||
} else {
|
||||
sPtr.rVal = iVal
|
||||
}
|
||||
idx = endIdx - 1
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
@@ -148,136 +118,150 @@ func ParseSnumStr(line string) Snum {
|
||||
}
|
||||
|
||||
func (s Snum) ToString() string {
|
||||
str := "["
|
||||
if s.lPtr != nil {
|
||||
str += s.lPtr.ToString()
|
||||
} else {
|
||||
str += fmt.Sprintf("%d", s.lVal)
|
||||
str := ""
|
||||
|
||||
for _, i := range s {
|
||||
switch i {
|
||||
case LBracket:
|
||||
str += "["
|
||||
case RBracket:
|
||||
str += "]"
|
||||
case Comma:
|
||||
str += ","
|
||||
default: // must be a number
|
||||
str += fmt.Sprintf("%d", i)
|
||||
}
|
||||
}
|
||||
str += ","
|
||||
if s.rPtr != nil {
|
||||
str += s.rPtr.ToString()
|
||||
} else {
|
||||
str += fmt.Sprintf("%d", s.rVal)
|
||||
}
|
||||
str += "]"
|
||||
|
||||
return str
|
||||
}
|
||||
|
||||
func AddSnum(s1, s2 Snum) Snum {
|
||||
log.Printf(log.DEBUG, " %s\n+ %s\n", s1.ToString(), s2.ToString())
|
||||
s := Snum{lPtr: &s1, rPtr: &s2}
|
||||
log.Printf(log.DIAGNOSTIC, " %s\n+ %s\n", s1.ToString(), s2.ToString())
|
||||
|
||||
s := append(Snum{LBracket}, s1...)
|
||||
s = append(s, Comma)
|
||||
s = append(s, s2...)
|
||||
s = append(s, RBracket)
|
||||
|
||||
s = s.Simplify()
|
||||
log.Printf(log.DEBUG, "= %s\n", s.ToString())
|
||||
log.Printf(log.DIAGNOSTIC, "= %s\n", s.ToString())
|
||||
|
||||
return s
|
||||
}
|
||||
|
||||
func (s1 Snum) Add(s2 Snum) Snum {
|
||||
log.Printf(log.DEBUG, " %s\n+ %s\n", s1.ToString(), s2.ToString())
|
||||
s := Snum{lPtr: &s1, rPtr: &s2}
|
||||
log.Printf(log.DIAGNOSTIC, " %s\n+ %s\n", s1.ToString(), s2.ToString())
|
||||
|
||||
s := append(Snum{LBracket}, s1...)
|
||||
s = append(s, Comma)
|
||||
s = append(s, s2...)
|
||||
s = append(s, RBracket)
|
||||
|
||||
s = s.Simplify()
|
||||
log.Printf(log.DEBUG, "= %s\n", s.ToString())
|
||||
log.Printf(log.DIAGNOSTIC, "= %s\n", s.ToString())
|
||||
|
||||
return s
|
||||
}
|
||||
|
||||
func (s Snum) Simplify() Snum {
|
||||
madeAChange := true
|
||||
for depth := 0; madeAChange; {
|
||||
madeAChange = false
|
||||
for sPtr := &s; sPtr != nil; {
|
||||
switch {
|
||||
case sPtr.ShouldExplode(depth):
|
||||
ExplodeValue(sPtr)
|
||||
madeAChange = true
|
||||
sPtr = nil
|
||||
depth := 0
|
||||
|
||||
// case sPtr.shouldSplit()
|
||||
|
||||
// travel the left side
|
||||
case sPtr.dir == LEFT:
|
||||
sPtr.dir = RIGHT
|
||||
if sPtr.lPtr != nil {
|
||||
sPtr = sPtr.lPtr
|
||||
depth++
|
||||
}
|
||||
// travel the right side
|
||||
case sPtr.dir == RIGHT:
|
||||
sPtr.dir = UP
|
||||
if sPtr.rPtr != nil {
|
||||
sPtr = sPtr.rPtr
|
||||
depth++
|
||||
}
|
||||
case sPtr.dir == UP:
|
||||
sPtr = sPtr.parentPtr
|
||||
depth--
|
||||
for idx := 0; idx < len(s); idx++ {
|
||||
switch s[idx] {
|
||||
case LBracket:
|
||||
depth++
|
||||
if s.ShouldExplodeAt(idx) {
|
||||
s.ExplodeAt(idx)
|
||||
idx = 0
|
||||
}
|
||||
case RBracket:
|
||||
depth--
|
||||
case Comma:
|
||||
continue
|
||||
default: // a number
|
||||
if s.ShouldSplitAt(idx) {
|
||||
s.SplitAt(idx)
|
||||
idx = 0
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// check to explode
|
||||
// check to split
|
||||
return s
|
||||
}
|
||||
|
||||
func (s Snum) IsNormal() bool {
|
||||
return s.lPtr == nil && s.rPtr == nil
|
||||
func (s Snum) DepthAt(pos int) int {
|
||||
depth := 0
|
||||
for _, i := range s[:pos+1] {
|
||||
if i == LBracket {
|
||||
depth++
|
||||
} else if i == RBracket {
|
||||
depth--
|
||||
}
|
||||
}
|
||||
|
||||
return depth
|
||||
}
|
||||
|
||||
func (s Snum) ShouldExplode(depth int) bool {
|
||||
return s.IsNormal() && depth > 3
|
||||
func (s Snum) IsNormalAt(pos int) bool {
|
||||
// the next few symbols should be "[#,#]"
|
||||
return pos+4 < len(s) && s[pos] == LBracket && s[pos+1] >= 0 && s[pos+3] >= 0
|
||||
}
|
||||
|
||||
func ExplodeValue(at *Snum) {
|
||||
log.Printf(log.DIAGNOSTIC, "Exploding the snum at %s\n", at.ToString())
|
||||
if !at.IsNormal() {
|
||||
panic("tried to explode a non-normal snum")
|
||||
}
|
||||
lVal, rVal := at.lVal, at.rVal
|
||||
var sPtr *Snum
|
||||
// explode left
|
||||
log.Printf(log.NEVER, "Starting at %s\n", at.parentPtr.ToString())
|
||||
for sPtr = at.parentPtr; sPtr.parentPtr != nil && sPtr.lPtr != nil; sPtr = sPtr.parentPtr {
|
||||
log.Printf(log.NEVER, " traveled left to %s\n", sPtr.ToString())
|
||||
}
|
||||
if sPtr != nil {
|
||||
log.Printf(log.NEVER, " added left %d to %d\n", lVal, sPtr.lVal)
|
||||
sPtr.lVal += lVal
|
||||
}
|
||||
|
||||
// explode right
|
||||
for sPtr = at.parentPtr; sPtr.parentPtr != nil && sPtr.rPtr != nil; {
|
||||
log.Printf(log.NEVER, " traveled right to %s\n", sPtr.ToString())
|
||||
sPtr = sPtr.parentPtr
|
||||
}
|
||||
if sPtr != nil {
|
||||
log.Printf(log.NEVER, " added right %d to %d\n", rVal, sPtr.rVal)
|
||||
sPtr.rVal += rVal
|
||||
}
|
||||
|
||||
// delete yourself
|
||||
pPtr := at.parentPtr
|
||||
if pPtr.lPtr == at {
|
||||
pPtr.lPtr = nil
|
||||
} else if pPtr.rPtr == at {
|
||||
pPtr.rPtr = nil
|
||||
}
|
||||
// the current read position and depth (for ease of calculation)
|
||||
func (s Snum) ShouldExplodeAt(pos int) bool {
|
||||
return s.IsNormalAt(pos) && s.DepthAt(pos) > 4
|
||||
}
|
||||
|
||||
func (s Snum) ShouldSplit() bool {
|
||||
return s.lVal > 9 || s.rVal > 9
|
||||
func (s *Snum) ExplodeAt(pos int) {
|
||||
log.Printf(log.DIAGNOSTIC, "Exploding the snum at %d: %s\n", pos, s.ToString())
|
||||
|
||||
lVal, rVal := (*s)[pos+1], (*s)[pos+3]
|
||||
// explode left!
|
||||
for idx := pos; idx > 0; idx-- {
|
||||
if (*s)[idx] >= 0 {
|
||||
(*s)[idx] += lVal
|
||||
break
|
||||
}
|
||||
}
|
||||
// explode right!
|
||||
for idx := pos + 4; idx < len(*s); idx++ {
|
||||
if (*s)[idx] >= 0 {
|
||||
(*s)[idx] += rVal
|
||||
break
|
||||
}
|
||||
}
|
||||
// replace the current snum with 0!
|
||||
*s = append((*s)[0:pos], append(Snum{0}, (*s)[pos+5:]...)...)
|
||||
}
|
||||
|
||||
func (s Snum) ShouldSplitAt(pos int) bool {
|
||||
return s[pos] > 9
|
||||
}
|
||||
|
||||
func (s *Snum) SplitAt(pos int) {
|
||||
lVal, rVal := int(math.Floor(float64((*s)[pos])/2)), int(math.Ceil(float64((*s)[pos])/2))
|
||||
log.Printf(log.DIAGNOSTIC, "Splitting the snum at %d: %d, adding values %d and %d\n", pos, (*s)[pos], lVal, rVal)
|
||||
|
||||
// Add a few extra values into the slice and then set the values
|
||||
*s = append((*s)[:pos+4], (*s)[pos:]...)
|
||||
(*s)[pos] = LBracket
|
||||
(*s)[pos+1] = lVal
|
||||
(*s)[pos+2] = Comma
|
||||
(*s)[pos+3] = rVal
|
||||
(*s)[pos+4] = RBracket
|
||||
}
|
||||
|
||||
func (s Snum) CalcMagnitude() int {
|
||||
lVal, rVal := s.lVal, s.rVal
|
||||
if s.lPtr != nil {
|
||||
lVal = s.lPtr.CalcMagnitude()
|
||||
for idx := 0; idx < len(s) && len(s) > 1; idx++ {
|
||||
if s.IsNormalAt(idx) {
|
||||
mVal := 3*s[idx+1] + 2*s[idx+3]
|
||||
log.Printf(log.DIAGNOSTIC, "Replacing %s with %d: ", s[idx:idx+5].ToString(), mVal)
|
||||
s = append(s[:idx+1], s[idx+5:]...)
|
||||
s[idx] = mVal
|
||||
idx = 0
|
||||
log.Printf(log.DIAGNOSTIC, "%s\n", s.ToString())
|
||||
}
|
||||
}
|
||||
if s.rPtr != nil {
|
||||
rVal = s.rPtr.CalcMagnitude()
|
||||
}
|
||||
|
||||
return 3*lVal + 2*rVal
|
||||
// when there's only one value left, that's the answer
|
||||
return 3*s[1] + 2*s[3]
|
||||
}
|
||||
Reference in new issue
Block a user