Create Sliding Puzzle.java (#589)

LeetCode/Sliding Puzzle.java

@@ -0,0 +1,49 @@
+class Solution {
+    public int slidingPuzzle(int[][] board) {
+        // Directions for possible swaps based on '0' position
+        int[][] dir = {{1, 3}, {0, 2, 4}, {1, 5}, {0, 4}, {1, 3, 5}, {2, 4}};
+        String target = "123450";
+        Set<String> vis = new HashSet<>(); // Track visited configurations
+        Queue<String> q = new LinkedList<>();
+        String start = "";
+
+        // Convert 2D board to a single string
+        for (int[] row : board) {
+            for (int col : row) {
+                start += col;
+            }
+        }
+
+        q.offer(start);
+        vis.add(start);
+        int step = 0;
+
+        // Perform BFS
+        while (!q.isEmpty()) {
+            int size = q.size();
+            while (size-- > 0) {
+                String current = q.poll();
+
+                // Check if target is reached
+                if (current.equals(target)) return step;
+
+                int zero = current.indexOf('0'); // Find position of '0'
+
+                // Generate next moves
+                for (int move : dir[zero]) {
+                    StringBuilder next = new StringBuilder(current);
+                    char temp = next.charAt(zero);
+                    next.setCharAt(zero, next.charAt(move));
+                    next.setCharAt(move, temp);
+
+                    if (!vis.contains(next.toString())) { // Add unvisited states to the queue
+                        vis.add(next.toString());
+                        q.offer(next.toString());
+                    }
+                }
+            }
+            step++;
+        }
+        return -1; // Return -1 if target is unreachable
+    }
+}