773 wrong answer

Author: aQua

Algorithms/0773.sliding-puzzle/sliding-puzzle.go

@@ -1,6 +1,64 @@
 package problem0773
 
+import (
+	"strings"
+)
+
 func slidingPuzzle(board [][]int) int {
+	hasSeen := make(map[string]bool, 720)
+	q := make([]string, 1, 720)
+	q[0] = convert(board)
+	hasSeen[q[0]] = true
+	target := "123450"
+
+	res := 0
+
+	if q[0] == target {
+		return res
+	}
+
+	d := []int{-1, 1, 3, -3}
+	size := len(q)
+	for len(q) > 0 {
+		s := q[0]
+		q = q[1:]
+		size--
+		if size == 0 {
+			size = len(q)
+			res++
+		}
+		i := strings.IndexByte(s, '0')
+		for k := range d {
+			j := i + d[k]
+			if j < 0 ||
+				j > 5 ||
+				i == 2 && j == 3 ||
+				i == 3 && j == 2 {
+				continue
+			}
+			b := []byte(s)
+			b[i], b[j] = b[j], b[i]
+
+			c := string(b)
+			if c == target {
+				return res
+			}
+
+			if !hasSeen[c] {
+				q = append(q, c)
+				hasSeen[c] = true
+			}
+		}
+
+	}
+
+	return -1
+}
 
-	return 0
+func convert(board [][]int) string {
+	res := make([]byte, 6)
+	for i := range res {
+		res[i] = byte(board[i/3][i%3]) + '0'
+	}
+	return string(res)
 }