二进制矩阵中的最短路径

/*
 * 思路：
 * 1. 使用Java Stream API不能直接用于BFS算法，但我们可以在过程中使用Stream来处理集合数据。
 * 2. 其余逻辑与传统Java实现类似。
 */

import java.util.LinkedList;
import java.util.Queue;
import java.util.stream.IntStream;

public class SolutionStream {
    public int shortestPathBinaryMatrix(int[][] grid) {
        int n = grid.length;
        if (grid[0][0] != 0 || grid[n - 1][n - 1] != 0) {
            return -1;
        }

        int[][] directions = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}, {1, 1}, {1, -1}, {-1, 1}, {-1, -1}};
        Queue<int[]> queue = new LinkedList<>();
        queue.offer(new int[]{0, 0, 1});
        grid[0][0] = 1;

        while (!queue.isEmpty()) {
            int[] current = queue.poll();
            int row = current[0];
            int col = current[1];
            int length = current[2];

            if (row == n - 1 && col == n - 1) {
                return length;
            }

            IntStream.range(0, directions.length).forEach(i -> {
                int newRow = row + directions[i][0];
                int newCol = col + directions[i][1];
                if (newRow >= 0 && newRow < n && newCol >= 0 && newCol < n && grid[newRow][newCol] == 0) {
                    queue.offer(new int[]{newRow, newCol, length + 1});
                    grid[newRow][newCol] = 1;
                }
            });
        }

        return -1;
    }
}