Package g0701_0800.s0773_sliding_puzzle

Class Solution

java.lang.Object
g0701_0800.s0773_sliding_puzzle.Solution
public class Solution extends java.lang.Object
773 - Sliding Puzzle.

Hard

On an 2 x 3 board, there are five tiles labeled from 1 to 5, and an empty square represented by 0. A move consists of choosing 0 and a 4-directionally adjacent number and swapping it.

The state of the board is solved if and only if the board is [[1,2,3],[4,5,0]].

Given the puzzle board board, return the least number of moves required so that the state of the board is solved. If it is impossible for the state of the board to be solved, return -1.

Example 1:

Input: board = [[1,2,3],[4,0,5]]

Output: 1

Explanation: Swap the 0 and the 5 in one move.

Example 2:

Input: board = [[1,2,3],[5,4,0]]

Output: -1

Explanation: No number of moves will make the board solved.

Example 3:

Input: board = [[4,1,2],[5,0,3]]

Output: 5

Explanation:

 5 is the smallest number of moves that solves the board.
 An example path:
 After move 0: [[4,1,2],[5,0,3]]
 After move 1: [[4,1,2],[0,5,3]]
 After move 2: [[0,1,2],[4,5,3]]
 After move 3: [[1,0,2],[4,5,3]]
 After move 4: [[1,2,0],[4,5,3]]
 After move 5: [[1,2,3],[4,5,0]]

Constraints:

  • board.length == 2
  • board[i].length == 3
  • 0 <= board[i][j] <= 5
  • Each value board[i][j] is unique.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    slidingPuzzle(int[][] board)
     
    java.lang.String
    swap(java.lang.String board, int y1, int x1, int y2, int x2)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • slidingPuzzle

      public int slidingPuzzle(int[][] board)

    • swap

      public java.lang.String swap(java.lang.String board, int y1, int x1, int y2, int x2)