第 2 题：合并二维有序数组成一维有序数组，归并排序的思路 about fe-interview

[Genzhen]

/**
 * 解题思路：
 * 双指针 从头到尾比较 两个数组的第一个值，根据值的大小依次插入到新的数组中
 * 空间复杂度：O(m + n)
 * 时间复杂度：O(m + n)
 * @param {Array} arr1
 * @param {Array} arr2
 */

function　merge(arr1, arr2){
    var　result=[];
    while(arr1.length>0 && arr2.length>0){
        if(arr1[0]<arr2[0]){
              /*shift()方法用于把数组的第一个元素从其中删除，并返回第一个元素的值。*/
            result.push(arr1.shift());
        }else{
            result.push(arr2.shift());
        }
    }
    return　result.concat(arr1).concat(arr2);
}

function mergeSort(arr){
    let lengthArr = arr.length;
    if(lengthArr === 0){
     return [];
    }
    while(arr.length > 1){
     let arrayItem1 = arr.shift();
     let arrayItem2 = arr.shift();
     let mergeArr = merge(arrayItem1, arrayItem2);
     arr.push(mergeArr);
    }
    return arr[0];
}
let arr1 = [[1,2,3],[4,5,6],[7,8,9],[1,2,3],[4,5,6]];
let arr2 = [[1,4,6],[7,8,10],[2,6,9],[3,7,13],[1,5,12]];
mergeSort(arr1);
mergeSort(arr2);

[Genzhen]

function mergeSort(arr) {
    const len = arr.length
    // 处理边界情况
    if(len <= 1) {
        return arr[0]
    }   
    // 计算分割点
    const mid = Math.floor(len / 2)    
    // 递归分割左子数组，然后合并为有序数组
    const leftArr = mergeSort(arr.slice(0, mid)) 
    // 递归分割右子数组，然后合并为有序数组
    const rightArr = mergeSort(arr.slice(mid,len))  
    // 合并左右两个有序数组
    arr = mergeArr(leftArr, rightArr)  
    // 返回合并后的结果
    return arr
}
  
function mergeArr(arr1, arr2) {  
    // 初始化两个指针，分别指向 arr1 和 arr2
    let i = 0, j = 0   
    // 初始化结果数组
    const res = []    
    // 缓存arr1的长度
    const len1 = arr1.length  
    // 缓存arr2的长度
    const len2 = arr2.length  
    // 合并两个子数组
    while(i < len1 && j < len2) {
        if(arr1[i] < arr2[j]) {
            res.push(arr1[i])
            i++
        } else {
            res.push(arr2[j])
            j++
        }
    }
    // 若其中一个子数组首先被合并完全，则直接拼接另一个子数组的剩余部分
    if(i<len1) {
        return res.concat(arr1.slice(i))
    } else {
        return res.concat(arr2.slice(j))
    }
}

var arr=[[1,2,4],[2,3,7],[3,5,7],[4,5,8]]
mergeArr(arr)

[ppmiao0628]

[[1,2,3],[4,5,6],[7,8,9],[1,2,3],[4,5,6]].flat(Infinity).sort((a,b)=>{ return a-b;})

[Genzhen]

// 方法1：使用concat
const flatten1 = (arr) => {
while (arr.some((item) => Array.isArray(item))) {
    arr = [].concat(...arr);
}
return arr;
};
// 方法2：使用reduce
const flatten2 = (arr) =>
arr.reduce(
    (acc, cur) =>
    Array.isArray(cur) ? [...acc, ...flatten2(cur)] : [...acc, cur],
    []
);
// test
var arr = [1, 2, [3, 4, [5, 6], 7, 8]];
console.log(flatten1(arr));
console.log(flatten2(arr));

[hehuilin]

function sortFlatArray (arr) {
		function flatArray (arr) {
			const newArr = arr.flat()
			return newArr.some(item => Array.isArray(item))? flatArray(newArr) : newArr
		}
		if (!arr || !arr.length) {
			return []
		}
		let flattenedArr = flatArray(arr)
		return flattenedArr.sort((a, b) => {
			return a - b
		})
	}

[gejianvs]

// 思路： 首先扁平化数组，再进行排序， 扁平化可以通过数组的tostring 和字符串split 方法
const arr =[[1,2,4],[2,3,7],[3,5,7],[4,5,8]]
const mySort = arr2 =>{
if(Array.isArray(arr2)){
const plantArr = arr2.toString().split(',')
plantArr.sort((a, b)=> a-b)
return plantArr
}
return []
}

console.log(mySort(arr))

[hehuilin]

// 方法1：使用concat
const flatten1 = (arr) => {
while (arr.some((item) => Array.isArray(item))) {
    arr = [].concat(...arr);
}
return arr;
};
// 方法2：使用reduce
const flatten2 = (arr) =>
arr.reduce(
    (acc, cur) =>
    Array.isArray(cur) ? [...acc, ...flatten2(cur)] : [...acc, cur],
    []
);
// test
var arr = [1, 2, [3, 4, [5, 6], 7, 8]];
console.log(flatten1(arr));
console.log(flatten2(arr));

这个是不是少了排序的功能，只做了将多维数组转换为一维数组

[chengming9731]

function merge (arr) {
      if (arr.length === 0) {
         return []
      }
      // 扁平化数组
      let newArr = arr.flat(Infinity)
      // 排序
      return newArr.sort(($1, $2) => $1 - $2)
   }
   merge([[1,2,3],[4,5,6],[7,8,9],[1,2,3],[4,5,6]])

不知道怎么调整格式凑合一下-_-

[work25]

let a = [1, 2, [3, 4, [5, 6]]]
let arr = []

function change(a) {
    a.forEach(item => {
        if (typeof item == 'object') {
            change(item)
        } else {
            arr.push(item)
        }
    })
}
change(a)
arr = arr.sort()

[HereSinceres]

const mergeArr = (arr) => {
	return arr.reduce((_memo,curr)=>{ return [..._memo,...curr].sort((a,b)=>a-b)},[])
}
mergeArr([[1,3],[2,4]])

[WJiaoJiao]

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

function mergeSort(arr) {
    let len = arr.length;
    if(len <= 1) return arr[0];
    let middleNum = Math.floor(len / 2);
    let left = arr.slice(0, middleNum);
    let right = arr.slice(middleNum);
    return merge(mergeSort(left), mergeSort(right));
}

function merge(left, right) {
    let result = [];
    while(left.length > 0 && right.length > 0) {
        if(left[0] < right[0]) {
            result.push(left.shift())
        }else {
            result.push(right.shift())
        }
    }
    while(left.length > 0) {
        result.push(left.shift());
    }
    while(right.length > 0) {
        result.push(right.shift());
    }
    return result;
}

mergeSort(arr);

[lion1ou]

function mergeArr(Arr) {
  function isArr(arr) {
    return Object.prototype.toString.call(arr) === "[object Array]";
  }
  if (!isArr(Arr)) {
    throw new Error("参数必须是数组");
  } else {
    if (Arr.length === 0 || !isArr(Arr[0])) {
      throw new Error("参数必须是二维数组");
    }
  }
  function sortMerge(Arr1, Arr2) {
    let i = 0;
    let j = 0;
    let result = [];
    if (Arr1.length === 0 || Arr2.length === 0) {
      return [...Arr1, ...Arr2];
    }
    while (i < Arr1.length || j < Arr2.length) {
      if (Arr1[i] < Arr2[j]) {
        result.push(Arr1[i]);
        i++;
      }
      if (Arr1[i] > Arr2[j]) {
        result.push(Arr2[j]);
        j++;
      }
      if (Arr1[i] === Arr2[j]) {
        result.push(Arr1[i]);
        i++;
        result.push(Arr2[j]);
        j++;
      }
      if (Arr1[i] === undefined && Arr2[j] !== undefined) {
        result.push(Arr2[j]);
        j++;
      }
      if (Arr1[i] !== undefined && Arr2[j] === undefined) {
        result.push(Arr1[i]);
        i++;
      }
    }
    return result;
  }
  return Arr.reduce((res, item) => {
    return sortMerge(res, item);
  }, []);
}

// 测试代码

var arr = [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9],
  [1, 2, 3, 21, 33, 45],
  [4, 5, 6],
];

var arr1 = [
  [1, 2, 4],
  [2, 3, 7],
  [3, 5, 7],
  [4, 5, 8],
];


console.log("result:", mergeArr(arr));
console.log("result:", mergeArr(arr1));

[zengxiaoluan]

let arr = [[1,20,30],[4,5,6],[-1,9,89,90]] // 我们的测试数组

let len = arr.length

let res = arr[0]
let index = 1
while(index < len) res = merge(res, arr[index++])


console.log(res)
// 利用数组元素已经排好序的事实
function merge (left, right) {
    let res = []
    while(left.length && right.length) {
        if(left[0] < right[0]) res.push(left.shift()) 
        else res.push(right.shift())
    }
    return res.concat(left, right)
}

[Mrfujianfei]

const merge = (arr1,arr2) => {
	const arr = [];
	while(arr1.length>1 && arr2.length>1){
		if(arr1[0] < arr2[0]){
			arr.push(arr1.shift())
		}else{
			arr.push(arr2.shift())
		}
	}
	return arr.concat(arr2).concat(arr1)
}

const mergeArr = (data) => {
	let arr = [];
	while(data.length >= 1){
		arr = merge(arr,data.shift())
	}
	return arr.sort((a,b)=>a-b);
}

[AAA611]

题目应该不是要直接把数组展平然后排序，那样的话我直接：

function sortTest(nums) {
  return nums.flat().sort((a, b) => a - b)
}

题目说是归并排序的思路，归并排序分为归和并两个过程

1. 归：把数组分为若干份分别将其排为有序数组
2. 并：把有序数组进行合并成为最终的排序结果

题目中给出的是多个有序数组，需要合并为一个有序数组，因此不需要“归”，直接“并”

function sort(nums) {
  let leftNums = nums[0]
  let res
  for (let i = 1; i < nums.length; i++) {
    res = []
    let rightNums = nums[i]
    let left = 0
    let right = 0
    while (left < leftNums.length && right < rightNums.length) {
      if (leftNums[left] < rightNums[right]) {
        res.push(leftNums[left])
        left++
      } else {
        res.push(rightNums[right])
        right++
      }
    }
    if (left < leftNums.length) {
      res.push(...leftNums.slice(left))
    }
    if (right < rightNums.length) {
      res.push(...rightNums.slice(right))
    }
    leftNums = res.slice()
  }
  return res
}

[hehuilin]

function sortFlatArray (arr) {
function flatArray (arr) {
const newArr = arr.flat()
return newArr.some(item => Array.isArray(item))? flatArray(newArr) : newArr
}
if (!arr || !arr.length) {
return []
}
let flattenedArr = flatArray(arr)
return flattenedArr.sort((a, b) => {
return a - b
})
}

数据长度的判断逻辑放在函数最开始是不是更好一点？

我是放在前面了呀，不知道你说的意思是要？

[SiHao24]

function sortFlatArray (arr) {
function flatArray (arr) {
const newArr = arr.flat()
return newArr.some(item => Array.isArray(item))? flatArray(newArr) : newArr
}
if (!arr || !arr.length) {
return []
}
let flattenedArr = flatArray(arr)
return flattenedArr.sort((a, b) => {
return a - b
})
}

数据长度的判断逻辑放在函数最开始是不是更好一点？

我是放在前面了呀，不知道你说的意思是要？

看错了，不好意思。

[123456zzz]

const mergeSort = (arr1: number[], arr2: number[]) => {
  const len1 = arr1.length,
    len2 = arr2.length;
  let i = 0,
    j = 0,
    arr = [];
  if (len1 === 0) return arr2;
  if (len2 === 0) return arr1;
  while (i < len1 || j < len2) {
    if (arr1[i] <= arr2[j] || j === len2) {
      arr.push(arr1[i]);
      i++;
    } else {
      arr.push(arr2[j]);
      j++;
    }
  }
  return arr;
};

//test

const arr1 = [1, 2, 3];
const arr2 = [2, 3, 4];
const arr3 = [1, 5, 6];

const arr = [arr1, arr2, arr3];

const res = arr.reduce((pre, cur) => mergeSort(pre, cur), []);

console.log(res);

[ppoollaarr]

function merge(left: number[], right: number[]): number[] {

    let result: number[] = [];
    while (left.length > 0 && right.length > 0) {
        if (left[0] <= right[0]) {
            result.push(left.shift());
        } else {
            result.push(right.shift());
        }
    }
    while (left.length > 0) {
        result.push(left.shift());
    }
    while (right.length > 0) {
        result.push(right.shift());
    }
    return result;
}

[HuberTRoy]

let tt = [
    [1,2,3,4,5],
    [8,9,10],
    [6,8,9],
]

function sort(arr) {
    if (!(arr instanceof Array)) {
        return
    }

    // 这里还应该有一个非 二维数组的判断。

    return arr.flat().sort((a, b) => {
        if (typeof(a) !== 'number' || typeof(a) !== 'bigint') {
            throw Error('Number need')
        }

        if (typeof(b) !== 'number' || typeof(b) !== 'bigint') {
            throw Error('Number need')
        }

        return a - b 
    })
}

console.log(sort(tt))

[523451928]

function flat(arr) {
  let copyArr = [...arr]
  while (copyArr.some(item => Array.isArray(item))) {
    copyArr = [].concat(...copyArr)
  }
  return copyArr.sort((a, b) => { a - b })
}
flat([[1, 2], [6, 4, 2], [3]])

[GolderBrother]

function flattenAndSort(arr = []) {
// 方法一: 借助concat方法
// function flatten(arr) {
// while (arr.some((item) => Array.isArray(item))) {
// arr = [].concat(...arr);
// }
// return arr;
// }

// 方法二: 借助reduce方法
// function flatten(arr = []) {
// return arr.reduce((accu, current) => {
// return Array.isArray(current)
// ? [...accu, ...flatten(current)]
// : [...accu, current];
// }, []);
// }

// 方法三: 直接使用数组的API flat, 传入Infinity值
function flatten(arr = []) {
return arr.flat(Infinity);
}

// 排序一个数组，我们先把数组从中间分成前后两部分，然后对前后两部分分别排序，再将排好序的两部分合并在一起，这样整个数组就都有序了。
// 归并排序采用的是分治**。
function mergeSort(arr = []) {
// 采用自上而下的递归方法
const len = arr.length;
if (len < 2) return arr;
const middleIndex = len >> 1,
left = arr.slice(0, middleIndex),
right = arr.slice(middleIndex);
// 开局就深度递归到子元素,然后再两两元素比较排序
return merge(mergeSort(left), mergeSort(right));
}
function merge(left = [], right = []) {
const result = [];
while (left.length && right.length) {
if (left[0] <= right[0]) {
// 类似队列的队首出队
result.push(left.shift());
} else {
result.push(right.shift());
}
}
// 如果还有剩余的元素，直接从头到尾放到数组尾部
while (left.length) result.push(left.shift());
while (right.length) result.push(right.shift());
return result;
}

return mergeSort(flatten(arr));
}

let arr = [
[1, 4, 6],
[7, 8, 10],
[2, 6, 9],
[3, 7, 13],
[1, 5, 12],
];
console.log(flattenAndSort(arr));

[JJL-SH]

const mergeSort = (arr) =>
arr.reduce((cacheArr, it) => [...cacheArr, ...it], []).sort((a, b) => a - b);
const arr = [[1, 2, 3], [6], [7, 8, 9], [1, 12, 13], [4, 5, 6]];
mergeSort(arr)

[huzedong2015]

const data = [
    [6, 7, 8, 9],
    [1, 2, 3, 4, 5],
    [10, 11, 12, 13]
];

const newData = data.flat();

newData.sort((a, b) => a - b);

如果是上面这种数据，可以先排序再扁平化数组

[jm19940203]

type flatReturn = Array;

export const flat = ( a: Array ): flatReturn => {

const newArr = a.toString().split(",");

return newArr.sort((a, b) => a - b);

}
//test
flat([[1, 2], [6, 4, 2], [3]])

[qiheng]

function mergeSort(arr) {

	let result = [];

	if (Array.isArray(arr)) {

		let newArr = JSON.parse(JSON.stringify(arr))

		while(newArr.length > 0) {

			let arrTmp = newArr.shift();

			result = result.concat(arrTmp)
			
		}

		result.sort(function(v1,v2) {
			return v1-v2
		})

	}

	return result

}

var arr = [[1,2,3],[4,5,6],[7,8,9],[1,2,3,21,45,33],[4,5,6]];

mergeSort(arr)

[noney]

/**
 * [mergeArrAndSort description]
 * @param  {Array}  arr    [二维数组]
 * @param  {Array}  resArr [结果数组]
 * @return {[type]}        [description]
 */
function mergeArrAndSort(arr = [], resArr = []) {
  for(let v of arr) {
    if (Array.isArray(v)) {
      mergeArrAndSort(v, resArr);
    } else {
      resArr.push(v);
    }
  }
  console.log(resArr.sort());
  return resArr.sort();
}

mergeArrAndSort([[1, 2], [2, 3], [4, 5, 7]]);
mergeArrAndSort([[1, 2], [2, 3], [4, 5, [6, 7, 8]]]);

[ruandao]

const mergeSort = (a: Array<number>, b: Array<number>): Array<number> => {
    if(a.length === 0) {
        return a
    }
    if(b.length === 0) {
        return b
    }
    const arr = [];
    let ai=0;
    let bi = 0;
    while(ai < a.length && bi < b.length) {
        if(a[ai] < b[bi]) {
            arr.push(a[ai]);
            ai++;
        } else {
            arr.push(b[bi]);
            bi++;
        }
    }
    for(;ai<a.length;ai++) {
        arr.push(a[ai])
    }
    for(;bi<b.length;bi++) {
        arr.push(b[bi])
    }
    return arr;
}
// 好吧，看错了....
const mergeSortArr = (arr: Array<number[]>): Array<number> => {
    if(!Array.isArray(arr)) {
        throw "传入的不是数组"
    }

    if(arr.length === 0) {
        throw "数组中至少需要一个元素"
    }
    if(arr.length === 1) {
        return arr[0];
    }
    return arr.slice(1).reduce((acc, item) => mergeSort(acc, item), arr[0])
}

var arr = [[1,2,3],[4,5,6],[7,8,9],[1,2,3,21,33, 45],[4,5,6]];

const result = mergeSortArr(arr)
console.log(result)

[chengazhen]

没有添加任何判断只是为了实现需求 不知道自己写的对不对 看上面大家都写了好多 是不是我理解错了啊

• 先利用flat进行扁平化处理
• 然后利用Set对象进行去重处理
• 利用from将set数组化
• 最后利用sort排序

 let arr = [
      [1, 4, 6],
      [7, 8, 10],
      [2, 6, 9],
      [3, 7, 13],
      [1, 5, 12]
    ];
//[[1,2,3],[4,5,6],[7,8,9],[1,2,3],[4,5,6]]

    function func(arr) {
      return Array.from(new Set(arr.flat(1))).sort((a, b) => a - b)
    }

//[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13]
// [1, 2, 3, 4, 5, 6, 7, 8, 9]

[markduan]

const arrayA = [1,3,5,7,9];
const arrayB = [111,221,331,441,551,661,771,881,991];
const arrayC = [2,4,5,6,8,10];
const arrayD = [11,22,33,44,55,66,77,88,99];
const matrix = [arrayA, arrayB, arrayC, arrayD]

function mergeArray(arrayA, arrayB) {
  let i = j = 0;
  const sortedArray = [];

  while(i < arrayA.length && j < arrayB.length) {
    if (arrayA[i] < arrayB[j]) {
      sortedArray.push(arrayA[i]);
      i += 1;
      continue
    }

    sortedArray.push(arrayB[j]);
    j += 1;
  }

  sortedArray.push(...arrayA.slice(i));
  sortedArray.push(...arrayB.slice(j));

  return sortedArray;
}

function flatMatrix(matrix) {
  return matrix.reduce((arrayA, arrayB) => {
    return mergeArray(arrayA, arrayB);
  });
}

console.log(flatMatrix(matrix));

[jieceng]

function mergeArray(arr){
return Array.prototype.concat.apply([],arr).sort()
}
let arr = [[1,2,3],[4,5,6],[7,8,9],[1,2,3],[4,5,6]];
console.log( mergeArray(arr) )

[lin09]

import _ from 'lodash'
console.log(.orderBy(.flatten(arr)))

[Cabzer-x]

let a = [[1,2,3],[1,1,2],[2,3,4]] let arr = a.reduce((prev,cur) => { return prev.concat(cur) },[]).sort((a,b) => { return a - b; })

[qinchao888]

function mergeSort(arr) {
  let left = arr.shift()
  let res = left
  while(arr.length) {
    let right = arr.shift()
    res = merge(res, right)
  }
  return res
}

function merge (left, right) { // 归并排序
  let i = 0, j = 0
  let res = []
  while(i < left.length && j < right.length) {
    if (left[i] < right[j]) {
      res.push(left[i])
      i++
    } else {
      res.push(right[j])
      j++
    }
  }
  while(i < left.length) {
    res.push(left[i])
    i++
  }
  while(j < right.length) {
    res.push(right[j])
    j++
  }
  return res
}
console.log(merge([1, 3, 5], [2, 3, 4, 8]))

[wulaoge]

function mergeArray(arr){
    let length = arr.length
    let mid = Math.floor(length/2)
    if(mid < 1) return arr[0]
    return mergeTwoArray(mergeArray(arr.slice(0,mid)),mergeArray(arr.slice(mid)))
}

function mergeTwoArray(arr1,arr2){
    let a1 = arr1.length - 1
    let a2 = arr2.length - 1
    let total = arr1.length + arr2.length - 1
    while(a2 >= 0){
        arr1[total--] =a1 >= 0 && arr1[a1] > arr2[a2]  ? arr1[a1--]: arr2[a2--] 
    }
    return  arr1
}

[m7yue]

const sort = (arr1, arr2) => {
  let res = [];
  let i = 0;
  let j = 0;
  while(i<arr1.length && j<arr2.length) {
    res.push(arr1[i] < arr2[j] ? arr1[i++] : arr2[j++]);
  }
  res = res.concat(i>=arr1.length ? arr2.slice(j) : arr1.slice(i))

  return res;
}

const mergeSort = (arr) => {
  if (arr.length <= 1) {
    return [...arr[0]];
  }
  const mid = Math.floor(arr.length/2);
  const left = arr.slice(0, mid);
  const right = arr.slice(mid);

  return sort(mergeSort(left), mergeSort(right));
}

var arr=[[1,2,4,6],[2,3,7,9],[3,5,6,7],[4,5,8,11]];
console.log(mergeSort(arr));

[Jam-Chu]

    // 合并两个数组
    function concatArr(leftArr, rightArr) {
      let auxArr = [];
      let leftIndex = 0, rightIndex = 0;
      while (leftIndex <= leftArr.length - 1 && rightIndex <= rightArr.length - 1) {
        if (leftArr[leftIndex] <= rightArr[rightIndex]) {
          auxArr.push(leftArr[leftIndex]);
          leftIndex++;
        } else {
          auxArr.push(rightArr[rightIndex]);
          rightIndex++;
        }
      }
      while (leftIndex <= leftArr.length - 1) {
        auxArr.push(leftArr[leftIndex]);
        leftIndex++;
      }
      while (rightIndex <= rightArr.length - 1) {
        auxArr.push(rightArr[rightIndex]);
        rightIndex++;
      }
      return auxArr;
    }
    // 递归定义：Darr从下标为start到end之间的所有数组合并为一个数组
    function mergeByrecursion(Darr, start, end) {
      if (start < end) {
        let mid = Math.floor((start + end) / 2);
        let leftArr = mergeByrecursion(Darr, start, mid);
        let rightArr = mergeByrecursion(Darr, mid + 1, end);
        return concatArr(leftArr, rightArr)
      } else {
        return Darr[start];
      }
    }
    // 归并入口
    let merge = function merge(Darr) {
      return mergeByrecursion(Darr, 0, Darr.length - 1);
    }
    // 测试用例
    let arr = [
      [1, 2, 5],
      [3, 6],
      [4, 8, 10],
      [9, 11, 12],
      [7, 13, 15, 17]
    ];
    console.log(merge(arr))

[Eryoo]

function merge (array){

	if(array.length == 0) return;

	let newArr = [];

	 this.init = function (arr){

		arr.forEach(item =>{

			if(Object.prototype.toString.call(item).indexOf('Array') > -1 && item.length > 1){

				this.init(item)

			}else{
				
				newArr.push(item)
			
			}
		});

	};


	this.init(array);

	return newArr.sort((a,b) => a - b)
}

[frankd318]

// CODE
const merge = (...arrs) => arrs.flat(Infinity).sort((a, b) => a - b ).reverse()

// TEST
const result = merge(
    [9, 8, 7],
    [100, 1000, 10000], 
    [4, 5, 6],
    0, -1, -2, -3, -4,
    { my: 1 }, null, '', new Object, false, true,
    [1, 2, 3]
)

console.log(result)

[db46rt00ors]

function mergeSort1(arr) {
            return arr.toString().split(',').map(item => +item).sort((a, b) => a - b)
        }

function mergeSort2(arr) { return arr.flat(Infinity).sort((a, b) => a - b) }

[hahazexia]

这个题目其实提出了两个问题，一个是数组的展平，一个是归并排序的实现。

利用 Generator 函数返回 Iterator 的特性，递归调用自己，然后使用扩展运算符将 Iterator 展开变成数组，归并排序直接使用标准实现就可以了。

function mergeSort (arr) {
    const len = arr.length;

    if (len < 2) {
        return arr;
    }

    const middle = Math.floor(len / 2),
        left = arr.slice(0, middle),
        right = arr.slice(middle);

    return merge(mergeSort(left), mergeSort(right));
}

function merge (left, right) {
    const result = [];

    while (left.length && right.length) {
        if (left[0] <= right[0]) {
            result.push(left.shift());
        } else {
            result.push(right.shift());
        }
    }

    while (left.length) {
        result.push(left.shift());
    }

    while (right.length) {
        result.push(right.shift());
    }

    return result;
}

function* flat (arr) {
    if (Array.isArray(arr)) {
        for (let i = 0; i < arr.length; i++) {
            yield* flat(arr[i]);
        }
    } else {
        yield arr;
    }
}

function mergeSortFlatten () {
    return mergeSort([...flat([...arguments])]);
}

let arr1 = [[1,2,3],[4,5,6],[7,8,9],[1,2,3],[4,5,6]];
let arr2 = [[1,4,6],[7,8,10],[2,6,9],[3,7,13],[1,5,12]];

mergeSortFlatten (arr1, arr2);
// [1, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 8, 8, 9, 9, 10, 12, 13]

[zjg910723]

let arr = [[1,2,3],[2,3,4],[4,5,6]]; let newArr = arr.reduce((a,b) => { return a.concat(b); }) console.log(newArr.sort())

[qq820137708]

function sortArr(arr){
    function flatArr(arr){
        return arr.flat()
    }
    let flatArray = flatArr(arr)
    return flatArray.sort((a,b)=>a-b)
}
let arr=[[1,10,4],[2,3,7],[3,5,7],[4,5,8]]
console.log(sortArr(arr))

[chjssg]

/**
 * 合并二维有序数组成一维有序数组，归并排序的思路[[1,2,3],[4,5,6,7,8,9]]*/

//[1,3,5,7,9],[2,4,6,7,8,9]
// 归并两个数组
function mergeArr(arr1,arr2){
    let result = []
    while (arr1.length||arr2.length) {
        if(arr1.length==0||arr2.length==0) {
            result.push(...arr2,...arr1)
            arr1=[]
            arr2=[]
        } else
        result.push(arr1[0]>arr2[0]?arr2.shift():arr1.shift())
    }
    console.log(result)
    return result
}
// mergeArr([1,3,5,7,9],[2,4,6,7,8,9])

function mergeArr2(arr) {
    let result = arr.shift()
    while (arr.length) {
        result = mergeArr(result, arr.shift())
    }
    console.log(result)
    return result
}

mergeArr2([[1,2,3],[4,5,6,7,8,9],[4,7,9,10]])

[Luoyuda]

    function mergeArr(arr){
        let n = arr.length;
        if(n <= 1) return arr[0];
        let m = Math.floor(n / 2)
        let left = mergeArr(arr.slice(0, m))
        let right = mergeArr(arr.slice(m))
        arr = merge(left, right)
        return arr
    }
    function merge(left, right) {
        let i = 0
        let j = 0
        let len1 = left.length
        let len2 = right.length
        let res = []
        while(i < len1 && j < len2){
            res[i + j] = left[i] < right[j] ? left[i++] : right[j++]
        }
        while(i < len1){
            res[i + j] = left[i++]
        }
        while(j < len2){
            res[i + j] = right[j++]
        }
        return res
    }

[CYLpursuit]

// 采用归并排序的思路，不断向结果数组中添加新数组进行归并
      function merge(leftArr, rightArr) {
        const result = [];
        while (leftArr.length > 0 && rightArr.length > 0) {
          if (leftArr[0] < rightArr[0]) {
            result.push(leftArr.shift());
          } else {
            result.push(rightArr.shift());
          }
        }
        return result.concat(leftArr).concat(rightArr);
      }
      function myMergeSortTwoDimension(twoDMSArr) {
        if (twoDMSArr.length <= 1) return twoDMSArr.shift();
        // 使用reduce
        return twoDMSArr.reduce(merge);
      }

[CYLpursuit]

[[1,2,3],[4,5,6],[7,8,9],[1,2,3],[4,5,6]].flat(Infinity).sort((a,b)=>{ return a-b;})

硬核

[CYLpursuit]

// 严格意义上的归并排序实现
function merge(leftArr, rightArr) {
      const result = [];
      if (leftArr[0] instanceof Array) {
        leftArr = leftArr.shift();
      }
      if (rightArr[0] instanceof Array) {
        rightArr = rightArr.shift();
      }
      while (leftArr.length > 0 && rightArr.length > 0) {
        if (leftArr[0] < rightArr[0]) {
          result.push(leftArr.shift());
        } else {
          result.push(rightArr.shift());
        }
      }

      return result.concat(leftArr).concat(rightArr);
    };
 function   myMergeSort(arr) {
      if (arr.length === 1) return arr;
      const middle = Math.floor(arr.length / 2);
      const leftArr = arr.slice(0, middle);
      const rightArr = arr.slice(middle);
      return merge(myMergeSort(leftArr), myMergeSort(rightArr));
    };

a = myMergeSort([[1,4,7],[2,5,8],[3,6,9]]);

[diuleiloumouF]

const sortFunc = (left, right) => {
if (!Array.isArray(left)) left = [left]
if (!Array.isArray(right)) right = [right]
const res = []
while (left.length > 0 && right.length > 0) {
if (left[0] < right[0]) {
res.push(left.shift())
} else {
res.push(right.shift())
}
}
return res.concat(left).concat(right)
}
const sort = arr => arr.reduce((pre, cur) => sortFunc(pre, cur))
console.log(sort([100, [1,4,6],[7,8,10],[2,6,9],[3,7,13],[1,5,12]]))

[Evllis]

没有添加任何判断只是为了实现需求 不知道自己写的对不对 看上面大家都写了好多 是不是我理解错了啊

• 先利用flat进行扁平化处理
• 然后利用Set对象进行去重处理
• 利用from将set数组化
• 最后利用sort排序

 let arr = [
      [1, 4, 6],
      [7, 8, 10],
      [2, 6, 9],
      [3, 7, 13],
      [1, 5, 12]
    ];
//[[1,2,3],[4,5,6],[7,8,9],[1,2,3],[4,5,6]]

    function func(arr) {
      return Array.from(new Set(arr.flat(1))).sort((a, b) => a - b)
    }

//[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13]
// [1, 2, 3, 4, 5, 6, 7, 8, 9]

如果碰到多维数据就废了，比如：

let arr = [1, 2, [3, 4, [5, 6, 7, 3, [10, 12]], 7, 8]];

当然你这个解题对二维数组是完全可以解决的，但我觉得应该尽量想的周全一点。
加油。

[Mr-wangyongqiang]

`let arrs = [[1, 2, [10, 12], 3], [5, 6, 8], [9, 4, 7]]

let newArr = []
function formatArr(arr) {
arr.forEach(item => {
if (Array.isArray(item)) {
formatArr(item)
}else{
newArr.push(item)
}
})
}

formatArr(arrs)

console.log(newArr.sort((a,b)=>a-b))`

[yuxiziyoutiankong]

 function flat(arr) {
  const l = []
  function dg (arr, p) {
    if (arr === p) return
    arr.forEach((item,index) => {
      if (item instanceof Array) {
        dg(item, arr)
      } else {
        l.push(item)
      }
    })
  }
  dg(arr)
  for(let i = 0; i < l.length; i++) {
    for(let j = i + 1; j < l.length; j++) {
      if (l[i] < l[j]) {
        let a = ''
        a = l[i]
        l[i] = l[j]
        l[j] = a
      }
    }
  }
  return l
}

[nhyu]

const fn = (arr) => [].concat(...arr).sort();
console.log(fn([[1, 3, 5], [2, 4, 6], [3, 5, 7]])); //=> [1, 2, 3, 3, 4, 5, 5, 6, 7]

[SnailOwO]

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

    // const arr1 = [1, 2, 4, 6, 9, 12, 15, 10, 3, 7, 8]

    function mergeSort(ary) {
        const len = ary.length
        if (len < 2) {
            return ary
        }
        const mid = Math.floor(len / 2)
        const left = ary.slice(0, mid)
        const right = ary.slice(mid)
        return merge(mergeSort(left), mergeSort(right))
    }

    function merge(ary1, ary2) {
        const result = []
        while (ary1.length && ary2.length) {
            if (ary1[0] <= ary2[0]) {
                result.push(ary1.shift())
            } else {
                result.push(ary2.shift())
            }
        }
        return result.concat(ary1).concat(ary2)
    }

    function flatAry(ary) {
        return Array.isArray(ary) ?
            ary.reduce((acc, cur) => [...acc, ...flatAry(cur)], []) : [ary]
    }

    // console.log(flatAry(ary))
    console.log(mergeSort(flatAry(ary)))
`

[18602435705]

/**
 * 合并两个一维有序数组
 * 双指针法
 * @param {Array} arr1
 * @param {Array} arr2
 * @returns
 */
function merge(arr1, arr2) {
  let result = [];
  let i = 0;
  let j = 0;
  for (
    let index = 0, length = arr1.length + arr2.length;
    index < length;
    index++
  ) {
    if (arr1[i] && arr2[j]) {
      if (arr1[i] <= arr2[j]) {
        result.push(arr1[i]);
        i++;
      } else {
        result.push(arr2[j]);
        j++;
      }
      continue;
    }
    if (arr1[i]) {
      result = [...result, ...arr1.slice(i)];
      break;
    }
    if (arr2[j]) {
      result = [...result, ...arr2.slice(j)];
      break;
    }
  }
  return result;
}

// 遍历二维数组，依次合并
function mergeSort(arr) {
  if (!arr.length) return [];
  let result = [];
  for (let i = 0; i < arr.length; i++) {
    result = merge(result, arr[i]);
  }
  console.log(result);
}

// 测试
const arr = [
  [1, 4, 6],
  [7, 8, 10],
  [2, 6, 9],
  [3, 7, 13],
  [1, 5, 12],
];

mergeSort(arr);

[18602435705]

/**
 * 合并两个一维有序数组
 * 首元素比较法
 * @param {Array} arr1
 * @param {Array} arr2
 * @returns {Array}
 */
function merge(arr1, arr2) {
  const [a, b] = [[...arr1], [...arr2]]; // 浅拷贝数组
  const result = [];
  while (a[0] && b[0]) {
    result.push(a[0] <= b[0] ? a.shift() : b.shift()); // 比较2个数组的第1个元素，谁小谁出列
  }
  return [...result, ...a, ...b];
}

// 遍历二维数组，依次合并
function mergeSort(arr) {
  if (!arr.length) return [];
  let result = [];
  for (let i = 0; i < arr.length; i++) {
    result = merge(result, arr[i]);
  }
  console.log(result);
}

// 测试
const arr = [
  [1, 4, 6],
  [7, 8, 10],
  [2, 6, 9],
  [3, 7, 13],
  [1, 5, 12],
];

mergeSort(arr);

[ty888]

function mergeSort(arr) {
    const len = arr.length
    // 处理边界情况
    if(len <= 1) {
        return arr[0]
    }   
    // 计算分割点
    const mid = Math.floor(len / 2)    
    // 递归分割左子数组，然后合并为有序数组
    const leftArr = mergeSort(arr.slice(0, mid)) 
    // 递归分割右子数组，然后合并为有序数组
    const rightArr = mergeSort(arr.slice(mid,len))  
    // 合并左右两个有序数组
    arr = mergeArr(leftArr, rightArr)  
    // 返回合并后的结果
    return arr
}
  
function mergeArr(arr1, arr2) {  
    // 初始化两个指针，分别指向 arr1 和 arr2
    let i = 0, j = 0   
    // 初始化结果数组
    const res = []    
    // 缓存arr1的长度
    const len1 = arr1.length  
    // 缓存arr2的长度
    const len2 = arr2.length  
    // 合并两个子数组
    while(i < len1 && j < len2) {
        if(arr1[i] < arr2[j]) {
            res.push(arr1[i])
            i++
        } else {
            res.push(arr2[j])
            j++
        }
    }
    // 若其中一个子数组首先被合并完全，则直接拼接另一个子数组的剩余部分
    if(i<len1) {
        return res.concat(arr1.slice(i))
    } else {
        return res.concat(arr2.slice(j))
    }
}

var arr=[[1,2,4],[2,3,7],[3,5,7],[4,5,8]]
mergeSort(arr)

[listen-amo]

简单来说，应该是归并排序少去从中分割的逻辑部分，直接进行合并排序的操作

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

console.log( merge(arr) );

function merge(arr) {
  let temp = [];
  for (let i = 0; i < arr.length; i++) {
    temp = sort(temp, arr[i]);
  }
  return temp;
}

function sort(a, b) {
  let temp = [];
  while (a.length && b.length) {
    temp.push(a[0] < b[0] ? a.shift() : b.shift());
  }
  return temp.concat(a, b);
}

[kangyana]

function flattenDeep(array, result = []) {
    array.forEach(item => {
        if (item.length) {
            flattenDeep(item, result);
        } else {
           result.push(item); 
        }
    })
    return result;
}

// 测试用例
var arr = [1, 2, [3, 4, [5, 6, 7, 3, [10, 12]], 7, 8]];
var num = flattenDeep(arr).sort((a, b) => a - b);
// => [1, 2, 3, 3, 4, 5, 6, 7, 7, 8, 10, 12]

[chenpengdepot]

function oneArry(arr){
arr=arr.flat();
arr=[...new Set(arr)].sort((a,b)=>{
return a-b
})
return arr;
}
let oldArr=[[1,2,4],[2,3,7],[3,5,7],[4,5,8]]
oldArr=oneArry(oldArr)
console.log(oldArr)

[HeroTangMy]

异步解决方案
`const testAry = [
[1, 23, 45, 99],
[4, 8, 9, 15, 48],
[4, 8, 17, 32],
[5, 7, 9]
]
async function tomerge(arr1, arr2) {
let mergedAry = [];
// console.log(arr1,arr2)
let longgerAry = arr1.length > arr2.length ? arr1 : arr2;
let shortAry=arr1.length < arr2.length ? arr1 : arr2;
let j = 0;
let i = 0;
while (shortAry.length != 0 || longgerAry.length != 0) {
if (shortAry.length == 0) {
mergedAry = mergedAry.concat(longgerAry)
break
}
if (longgerAry.length == 0) {
mergedAry = mergedAry.concat(shortAry)
break
}
if (shortAry[0] > longgerAry[0]) {
// console.log(mergedAry)
mergedAry.push(longgerAry.shift())
}
else {
// console.log(mergedAry)
mergedAry.push(shortAry.shift())
}
}
return mergedAry

}
function merge(thisary) {
    let promiseArr = []
    // console.log(thisary)
    if (thisary.length % 2 === 1) {
        thisary.push([])
    }
    return new Promise((resolve, reject) => {
        while (thisary.length >= 2) {
            // console.log(thisary[0], thisary[1])
            promiseArr.push(tomerge(thisary[0], thisary[1]))
            thisary.shift()
            thisary.shift()
        }
        console.log(promiseArr)
        Promise.all(promiseArr).then(NextNums => {
            if (NextNums.length === 1) {
                // console.log(NextNums[0])
                resolve(NextNums[0])
            } else {
                // console.log(NextNums)
                merge(NextNums).then(res => {
                    resolve(res)
                })
            }
        })
    })
}

merge(testAry).then(info => { console.log(info) })`

[wringY]

    function mergeSort(leftArr, rightArr) {
        
        const left = leftArr.flat(Infinity)
        const right = rightArr.flat(Infinity)

        let result = []
        let i = 0, j = 0;
        while (i < left.length && j < right.length) {
            if (left[i] <= right[j]) {
                result.push(left[i])
                i++
            } else {
                result.push(right[j])
                j++
            }
        }

        if ( i < left.length) {
            result.push(...left.slice(i))
        } else {
            result.push(...right.slice(j))
        }

        return result
    }
    console.log(mergeSort([[0, 1],[2, 3], [4, 5]], [[6, 7],[8, 9], [10, 11]]))

[nanmu-yuan]

const arr1 = [[5,9,6],[5,9,6,],[8,9,6]];
const mergeAndSex = (arr)=>[].concat(...arr).sort((a,b)=>a-b)