Sha256: d028d551ad6da2547d735d9a3093d97e76e621707d7fe7eb56b71ec928756472
Contents?: true
Size: 1.6 KB
Versions: 122
Compression:
Stored size: 1.6 KB
Contents
package wordsearch
import "fmt"
func Solve(words []string, puzzle []string) (map[string][2][2]int, error) {
positions := make(map[string][2][2]int, len(words))
for _, word := range words {
span, err := find(word, puzzle)
if err != nil {
return nil, err
}
positions[word] = span
}
return positions, nil
}
type dir struct {
cx, cy int
}
var (
north = dir{0, -1}
northeast = dir{1, -1}
east = dir{1, 0}
southeast = dir{1, 1}
south = dir{0, 1}
southwest = dir{-1, 1}
west = dir{-1, 0}
northwest = dir{-1, -1}
)
var dirs = []dir{north, northeast, east, southeast, south, southwest, west, northwest}
var zeroSpan = [2][2]int{{0, 0}, {0, 0}}
func find(word string, puzzle []string) ([2][2]int, error) {
for x := 0; x < len(puzzle[0]); x++ {
for y := 0; y < len(puzzle); y++ {
for _, dir := range dirs {
if span, ok := try(word, puzzle, x, y, dir); ok {
return span, nil
}
}
}
}
return zeroSpan, fmt.Errorf("Didn't find %q", word)
}
func try(word string, puzzle []string, startX, startY int, dir dir) ([2][2]int, bool) {
x, y := startX, startY
for _, c := range word {
if lc, ok := lookup(x, y, puzzle); !ok || lc != c {
return zeroSpan, false
}
x += dir.cx
y += dir.cy
}
// Need to remove the last increment to get the position of the last character.
return [2][2]int{{startX, startY}, {x - dir.cx, y - dir.cy}}, true
}
func lookup(x, y int, puzzle []string) (rune, bool) {
if x >= 0 && x < len(puzzle[0]) && y >= 0 && y < len(puzzle) {
// Yes, yes, this won't work with multi-byte codepoints.
return rune(puzzle[y][x]), true
}
return 0, false
}
Version data entries
122 entries across 122 versions & 1 rubygems