计算一个项目在javascript的多维数组中出现的次数

let twoDimensionalArray = [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]
];

let threeDimensionalArray = [
  [
    [1, 2],
    [3, 4]
  ],
  [
    [5, 6],
    [7, 8]
  ]
];

function countOccurrences(arr, target) {
  let count = 0;

  function traverse(array) {
    for (let i = 0; i < array.length; i++) {
      if (Array.isArray(array[i])) {
        traverse(array[i]);
      } else if (array[i] === target) {
        count++;
      }
    }
  }

  traverse(arr);
  return count;
}

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

console.log(countOccurrences(multiDimensionalArray, 3)); // 输出: 3

function countOccurrencesIterative(arr, target) {
  let count = 0;
  let stack = [...arr];

  while (stack.length) {
    let current = stack.pop();
    if (Array.isArray(current)) {
      stack.push(...current);
    } else if (current === target) {
      count++;
    }
  }

  return count;
}