寻找二维数组中四个邻域的最大值

function findMaxInNeighborhood(matrix) {
  const rows = matrix.length;
  const cols = matrix[0].length;
  const result = [];

  for (let i = 0; i < rows; i++) {
    result[i] = [];
    for (let j = 0; j < cols; j++) {
      const neighbors = [];

      // 上邻域
      if (i > 0) {
        neighbors.push(matrix[i - 1][j]);
      }
      // 下邻域
      if (i < rows - 1) {
        neighbors.push(matrix[i + 1][j]);
      }
      // 左邻域
      if (j > 0) {
        neighbors.push(matrix[i][j - 1]);
      }
      // 右邻域
      if (j < cols - 1) {
        neighbors.push(matrix[i][j + 1]);
      }

      // 找出邻域的最大值
      const maxNeighbor = Math.max(...neighbors);

      result[i][j] = maxNeighbor;
    }
  }

  return result;
}

// 示例用法
const matrix = [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]
];

const maxInNeighborhood = findMaxInNeighborhood(matrix);
console.log(maxInNeighborhood);

[
  [5, 6, 6],
  [8, 9, 9],
  [8, 9, 9]
]