adventofcode/2020/day12/ship.go

130 lines
2.2 KiB
Go

package main
import h "git.bullercodeworks.com/brian/adventofcode/helpers"
type Ship struct {
Pos h.Coordinate
Dir int
Waypoint h.Coordinate
ByWaypoint bool
}
func (s *Ship) Navigate(inp []string) {
for i := range inp {
cmd, dist := inp[i][0], h.Atoi(inp[i][1:])
switch cmd {
case 'N':
if s.ByWaypoint {
s.MoveWaypoint(N, dist)
} else {
s.MoveDirection(N, dist)
}
case 'S':
if s.ByWaypoint {
s.MoveWaypoint(S, dist)
} else {
s.MoveDirection(S, dist)
}
case 'E':
if s.ByWaypoint {
s.MoveWaypoint(E, dist)
} else {
s.MoveDirection(E, dist)
}
case 'W':
if s.ByWaypoint {
s.MoveWaypoint(W, dist)
} else {
s.MoveDirection(W, dist)
}
case 'L':
if s.ByWaypoint {
s.RotateWaypointLeft(dist)
} else {
s.TurnLeft(dist)
}
case 'R':
if s.ByWaypoint {
s.RotateWaypointRight(dist)
} else {
s.TurnRight(dist)
}
case 'F':
if s.ByWaypoint {
s.MoveToWaypoint(dist)
} else {
s.MoveDirection(s.Dir, dist)
}
}
}
}
func (s *Ship) MoveDirection(dir int, dist int) {
switch dir {
case N:
s.Pos.Y = s.Pos.Y - dist
case E:
s.Pos.X = s.Pos.X + dist
case S:
s.Pos.Y = s.Pos.Y + dist
case W:
s.Pos.X = s.Pos.X - dist
}
}
func (s *Ship) TurnRight(deg int) {
deg = deg % 360
for deg > 0 {
s.Dir = s.Dir + 1
deg = deg - 90
}
s.Dir = s.Dir % (W + 1)
}
func (s *Ship) TurnLeft(deg int) {
deg = deg % 360
for deg > 0 {
s.Dir = s.Dir - 1
deg = deg - 90
if s.Dir == -1 {
s.Dir = W
}
}
}
func (s *Ship) MoveToWaypoint(times int) {
for i := times; i > 0; i-- {
s.Pos.X += s.Waypoint.X
s.Pos.Y += s.Waypoint.Y
}
}
func (s *Ship) MoveWaypoint(dir int, dist int) {
switch dir {
case N:
s.Waypoint.Y = s.Waypoint.Y - dist
case E:
s.Waypoint.X = s.Waypoint.X + dist
case S:
s.Waypoint.Y = s.Waypoint.Y + dist
case W:
s.Waypoint.X = s.Waypoint.X - dist
}
}
func (s *Ship) RotateWaypointLeft(deg int) {
deg = deg % 360
for deg > 0 {
s.Waypoint.X, s.Waypoint.Y = s.Waypoint.Y, s.Waypoint.X*-1
deg = deg - 90
}
}
func (s *Ship) RotateWaypointRight(deg int) {
deg = deg % 360
for deg > 0 {
s.Waypoint.X, s.Waypoint.Y = s.Waypoint.Y*-1, s.Waypoint.X
deg = deg - 90
}
}