chore(day17): fix missing changes #20

Merged
xuu merged 1 commits from day17-fixes into main 2024-01-01 09:58:33 -07:00
2 changed files with 24 additions and 9 deletions

View File

@ -129,9 +129,16 @@ func (g *graph) Potential(a, b position) int16 {
return aoc.ManhattanDistance(a.loc, b.loc)
}
func (g *graph) Target(a position) bool {
if a.loc == g.target && a.steps >= g.min {
return true
}
return false
}
// Seen attempt at simplifying the seen to use horizontal/vertical and no steps.
// It returns correct for part1 but not part 2..
// func (g *pather) Seen(a position) position {
// func (g *graph) Seen(a position) position {
// if a.direction == U {
// a.direction = D
// }

View File

@ -43,8 +43,11 @@ type pather[C number, N any] interface {
Cost(a, b N) C
Potential(a, b N) C
// OPTIONAL: modify value used by seen pruning.
// OPTIONAL:
// Seen modify value used by seen pruning.
// Seen(N) N
// Target returns true if target reached.
// Target(N) bool
}
type Path[C number, N any] []N
@ -57,16 +60,16 @@ func FindPath[C integer, N comparable](g pather[C, N], start, end N) (C, Path[C,
cost C
potential C
parent *node
last N
position N
}
NewPath := func(n *node) []N {
var path []N
for n.parent != nil {
path = append(path, n.last)
path = append(path, n.position)
n = n.parent
}
path = append(path, n.last)
path = append(path, n.position)
Reverse(path)
return path
@ -77,7 +80,7 @@ func FindPath[C integer, N comparable](g pather[C, N], start, end N) (C, Path[C,
}
pq := PriorityQueue(less)
pq.Enqueue(node{last: start})
pq.Enqueue(node{position: start})
defer func() {
fmt.Println("queue max depth = ", pq.maxDepth, "total enqueue = ", pq.totalEnqueue)
@ -88,9 +91,14 @@ func FindPath[C integer, N comparable](g pather[C, N], start, end N) (C, Path[C,
seenFn = s.Seen
}
var targetFn = func(a N) bool { return true }
if s, ok := g.(interface{ Target(N) bool }); ok {
targetFn = s.Target
}
for !pq.IsEmpty() {
current, _ := pq.Dequeue()
cost, potential, n := current.cost, current.potential, current.last
cost, potential, n := current.cost, current.potential, current.position
seen := seenFn(n)
if closed[seen] {
@ -98,7 +106,7 @@ func FindPath[C integer, N comparable](g pather[C, N], start, end N) (C, Path[C,
}
closed[seen] = true
if cost > 0 && potential == zero {
if cost > 0 && potential == zero && targetFn(current.position) {
return cost, NewPath(&current)
}
@ -110,7 +118,7 @@ func FindPath[C integer, N comparable](g pather[C, N], start, end N) (C, Path[C,
cost := g.Cost(n, nb) + current.cost
nextPath := node{
last: nb,
position: nb,
parent: &current,
cost: cost,
potential: g.Potential(nb, end),