二维数组

查找目标值

var findNumberIn2DArray = function (matrix, target) {
  if (matrix == null || matrix.length == 0) {
    return false
  }
  let row = 0
  let column = matrix[0].length - 1
  while (row < matrix.length && column >= 0) {
    if (matrix[row][column] == target) {
      return true
    } else if (matrix[row][column] > target) {
      column--
    } else {
      row++
    }
  }
  return false
}

斜向打印

function printMatrix(arr) {
  let m = arr.length
  let n = arr[0].length
  let res = []

  // 左上角，从 0 到 n - 1 列进行打印
  for (let k = 0; k < n; k++) {
    for (let i = 0, j = k; i < m && j >= 0; i++, j--) {
      res.push(arr[i][j])
    }
  }

  // 右下角，从 1 到 n - 1 行进行打印
  for (let k = 1; k < m; k++) {
    for (let i = k, j = n - 1; i < m && j >= 0; i++, j--) {
      res.push(arr[i][j])
    }
  }
  return res
}