Class Solution


  • public class Solution
    extends Object
    1210 - Minimum Moves to Reach Target with Rotations\. Hard In an `n*n` grid, there is a snake that spans 2 cells and starts moving from the top left corner at `(0, 0)` and `(0, 1)`. The grid has empty cells represented by zeros and blocked cells represented by ones. The snake wants to reach the lower right corner at `(n-1, n-2)` and `(n-1, n-1)`. In one move the snake can: * Move one cell to the right if there are no blocked cells there. This move keeps the horizontal/vertical position of the snake as it is. * Move down one cell if there are no blocked cells there. This move keeps the horizontal/vertical position of the snake as it is. * Rotate clockwise if it's in a horizontal position and the two cells under it are both empty. In that case the snake moves from `(r, c)` and `(r, c+1)` to `(r, c)` and `(r+1, c)`. ![](https://assets.leetcode.com/uploads/2019/09/24/image-2.png) * Rotate counterclockwise if it's in a vertical position and the two cells to its right are both empty. In that case the snake moves from `(r, c)` and `(r+1, c)` to `(r, c)` and `(r, c+1)`. ![](https://assets.leetcode.com/uploads/2019/09/24/image-1.png) Return the minimum number of moves to reach the target. If there is no way to reach the target, return `-1`. **Example 1:** **![](https://assets.leetcode.com/uploads/2019/09/24/image.png)** **Input:** grid = [ [0,0,0,0,0,1], [1,1,0,0,1,0], [0,0,0,0,1,1], [0,0,1,0,1,0], [0,1,1,0,0,0], [0,1,1,0,0,0]] **Output:** 11 **Explanation:** One possible solution is [right, right, rotate clockwise, right, down, down, down, down, rotate counterclockwise, right, down]. **Example 2:** **Input:** grid = [ [0,0,1,1,1,1], [0,0,0,0,1,1], [1,1,0,0,0,1], [1,1,1,0,0,1], [1,1,1,0,0,1], [1,1,1,0,0,0]] **Output:** 9 **Constraints:** * `2 <= n <= 100` * `0 <= grid[i][j] <= 1` * It is guaranteed that the snake starts at empty cells.
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • minimumMoves

        public int minimumMoves​(int[][] grid)