LeetCode - 2624.蜗牛排序

这一题对我来说有些难度，起码是要看题解才能明白的程度，其核心思路就是从二维数组来设计，得到其最大长度，一行一行的从上往下，或从下往上进行填充

要求

1. rows * cols != length 无效

   let nums = [19, 10, 3, 7, 9, 8, 5, 2, 1, 17, 16, 14, 12, 18, 6, 13, 11, 20, 4, 15]
   let rowsCount = 5
   let colsCount = 4
   /*
   [
    [19,17,16,15],
    [10,1,14,4],
    [3,2,12,20],
    [7,5,18,11],
    [9,8,6,13]
   ]
   */

   题解

   Array.prototype.snail = function (rowsCount, colsCount) {
     if (rowsCount * colsCount !== this.length) return false;
   
     let resAry = Array.from({ length: rowsCount }, () => []); // 创建对应二维数组
   
     let seq = true; //默认从上往下 true 否则false相反
     let start = 0; //记录行数 如果到达最大行数则使seq相反
   
     for (let i = 0; i < this.length; i++) {
    resAry[start].push(this[i]); //填充
    // 如果是从上往下 则判断是否到达最大行数，到达则相反 否则再继续往下
    // 反过来也一样
    if (seq) {
      if (start === rowsCount - 1) {
        seq = false;
      } else {
        start++;
      }
    } else {
      if (start === 0) {
        seq = true;
      } else {
        start--;
      }
    }
     }
     return resAry;
   };
   
   let nums = [
     19, 10, 3, 7, 9, 8, 5, 2, 1, 17, 16, 14, 12, 18, 6, 13, 11, 20, 4, 15,
   ];
   
   console.log(nums.snail(5, 4));