parent
ef98db2967
commit
3d7ac83d3f
@ -0,0 +1,215 @@ |
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package main |
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|
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import ( |
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"bufio" |
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"fmt" |
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"log" |
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"math" |
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"os" |
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"strconv" |
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"strings" |
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) |
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var particles map[int]*Particle |
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var confidenceThreshold int |
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func main() { |
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inp := StdinToStrings() |
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particles = make(map[int]*Particle) |
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for i := range inp { |
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particles[i] = NewParticle(inp[i], i) |
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} |
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confidenceThreshold = 1000 |
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doPart := 2 |
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if len(os.Args) > 1 { |
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if os.Args[1] == "-1" { |
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doPart = 1 |
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} |
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} |
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switch doPart { |
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case 1: |
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part1(inp) |
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case 2: |
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part2(inp) |
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} |
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} |
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func part1(inp []string) { |
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var ticks, confidence, last int |
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cPart := -1 |
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for { |
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cDist := 10000000000 |
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ticks++ |
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for i := range particles { |
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particles[i].Tick() |
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if particles[i].GetDistance() < cDist { |
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cPart = i |
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cDist = particles[i].GetDistance() |
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} |
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} |
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if cPart == last { |
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confidence++ |
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} else { |
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confidence = 0 |
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last = cPart |
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} |
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if confidence >= confidenceThreshold { |
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break |
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} |
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} |
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fmt.Println("After", ticks, "the closest is", cPart) |
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} |
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|
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func part2(inp []string) { |
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var ticks, lastNum, confidence int |
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for { |
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ticks++ |
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for i := range particles { |
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particles[i].Tick() |
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} |
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var collisions []int |
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for k1, v1 := range particles { |
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for k2, v2 := range particles { |
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if k1 == k2 { |
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continue |
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} |
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if v1.Collides(v2) { |
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collisions = AddToSlice(collisions, k1) |
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collisions = AddToSlice(collisions, k2) |
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break |
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} |
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} |
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} |
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for i := len(collisions) - 1; i >= 0; i-- { |
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delete(particles, collisions[i]) |
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} |
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if len(particles) == lastNum { |
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confidence++ |
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} else { |
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confidence = 0 |
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lastNum = len(particles) |
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} |
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if confidence >= confidenceThreshold { |
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break |
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} |
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} |
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fmt.Println("After", ticks, "there are", len(particles), "particles left") |
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} |
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func AddToSlice(sl []int, v int) []int { |
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for i := range sl { |
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if sl[i] == v { |
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return sl |
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} |
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} |
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sl = append(sl, v) |
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return sl |
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} |
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type Coordinate struct { |
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X, Y, Z int |
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} |
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func NewCoordinate(inp string) Coordinate { |
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inp = inp[1 : len(inp)-1] |
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pts := strings.Split(inp, ",") |
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px, py, pz := Atoi(pts[0]), Atoi(pts[1]), Atoi(pts[2]) |
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return Coordinate{X: px, Y: py, Z: pz} |
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} |
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func (c *Coordinate) toString() string { |
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return fmt.Sprintf("<%d,%d,%d>", c.X, c.Y, c.Z) |
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} |
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type Particle struct { |
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Index int |
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Position Coordinate |
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Velocity Coordinate |
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Acceleration Coordinate |
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LastPosition Coordinate |
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} |
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func NewParticle(inp string, idx int) *Particle { |
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ret := new(Particle) |
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ret.Index = idx |
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pts := strings.Split(inp, " ") |
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for i := range pts { |
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keyVal := strings.Split(pts[i], "=") |
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if keyVal[1][len(keyVal[1])-1] == ',' { |
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keyVal[1] = keyVal[1][:len(keyVal[1])-1] |
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} |
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switch keyVal[0] { |
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case "p": |
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ret.Position = NewCoordinate(keyVal[1]) |
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case "v": |
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ret.Velocity = NewCoordinate(keyVal[1]) |
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case "a": |
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ret.Acceleration = NewCoordinate(keyVal[1]) |
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} |
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} |
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ret.LastPosition = NewCoordinate(ret.Position.toString()) |
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return ret |
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} |
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func (p *Particle) Collides(tst *Particle) bool { |
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if p.Position.X == tst.Position.X && |
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p.Position.Y == tst.Position.Y && |
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p.Position.Z == tst.Position.Z { |
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return true |
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} |
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return false |
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} |
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func (p *Particle) String() string { |
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return fmt.Sprintf( |
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"p=<%d,%d,%d>, v=<%d,%d,%d>, a=<%d,%d,%d>", |
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p.Position.X, p.Position.Y, p.Position.Z, |
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p.Velocity.X, p.Velocity.Y, p.Velocity.Z, |
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p.Acceleration.X, p.Acceleration.Y, p.Acceleration.Z, |
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) |
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} |
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func (p *Particle) Tick() { |
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p.LastPosition = NewCoordinate(p.Position.toString()) |
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p.Velocity.X += p.Acceleration.X |
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p.Velocity.Y += p.Acceleration.Y |
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p.Velocity.Z += p.Acceleration.Z |
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p.Position.X += p.Velocity.X |
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p.Position.Y += p.Velocity.Y |
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p.Position.Z += p.Velocity.Z |
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} |
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func (p *Particle) IsDone() bool { |
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return p.GetDistance() == p.GetLastDistance() |
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} |
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func (p *Particle) GetDistance() int { |
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return GetAbs(p.Position.X) + GetAbs(p.Position.Y) + GetAbs(p.Position.Z) |
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} |
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func (p *Particle) GetLastDistance() int { |
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return int(math.Abs(float64(p.LastPosition.X + p.LastPosition.Y + p.LastPosition.Z))) |
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} |
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func StdinToStrings() []string { |
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var input []string |
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scanner := bufio.NewScanner(os.Stdin) |
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for scanner.Scan() { |
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input = append(input, scanner.Text()) |
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} |
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return input |
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} |
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func GetAbs(v int) int { |
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return int(math.Abs(float64(v))) |
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} |
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func Atoi(i string) int { |
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var ret int |
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var err error |
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if ret, err = strconv.Atoi(i); err != nil { |
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log.Fatal("Invalid Atoi") |
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} |
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return ret |
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} |
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File diff suppressed because it is too large
Load Diff
@ -0,0 +1,2 @@ |
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p=<3,0,0>, v=<2,0,0>, a=<-1,0,0> |
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p=<4,0,0>, v=<0,0,0>, a=<-2,0,0> |
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