2020 Day 12 Complete

2020-12-12 09:49:05 -06:00
parent 772298895b
commit d6c150e840
12 changed files with 964 additions and 0 deletions
--- a/2020/day12/ship.go
+++ b/2020/day12/ship.go
@@ -0,0 +1,129 @@
+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
+	}
+}