删除多维数组中的重复数据

function removeDuplicates(arr) {
  let flattenedArr = arr.flat(Infinity); // 将多维数组转为一维数组
  let uniqueArr = [];
  let hashTable = {};

  for (let i = 0; i < flattenedArr.length; i++) {
    let element = flattenedArr[i];
    if (!hashTable[element]) {
      hashTable[element] = true;
      uniqueArr.push(element);
    }
  }

  return uniqueArr;
}

// 示例用法
let arr = [[1, 2, 3], [4, 5, 6], [1, 2, 3], [7, 8, 9]];
let result = removeDuplicates(arr);
console.log(result); // 输出: [[1, 2, 3], [4, 5, 6], [7, 8, 9]]