数组未定义 - Codewars Kata Round Robin Tournament

Question

我正在尝试这样做 Kata - https://www.codewars.com/kata/organize-a-round-robin-tournament/train/javascript。

任务是创建一个组织循环赛的函数。

例子：

buildMatchesTable(4)

应该返回一个像这样的矩阵：

[
  [[1,2], [3, 4]],  // first round:  1 vs 2, 3 vs 4
  [[1,3], [2, 4]],  // second round: 1 vs 3, 2 vs 4
  [[1,4], [2, 3]]   // third round:  1 vs 4, 2 vs 3
]

我创建了一个非常笨拙的解决方案，直到最后一个障碍。我留下了一个数组 (arr6)，它是一个以正确顺序列出所有比赛的数组，但它是一个简单的数组，而不是指定各个回合的子数组。所以我尝试创建一个函数 cut 以生成正确格式的数组，它告诉我 arr7 未定义。

我的解决方案写得不好，因为我是新手，但我认为修复应该相对简单，与在函数中未正确返回值或以错误顺序调用函数有关。谢谢。

function buildMatchesTable(numberOfTeams) {
  let n = numberOfTeams; let h = n/2; let arr = []; let arr2 = [[],[]];
  let arr3 = [...Array(n-1)].map(v => v); let arr4 = [];
//create array
for (var i = 1; i <= n; i++) {arr.push(i)} //[1, 2, 3, 4]
//split array
arr2[0] = arr.splice(0, arr.length/2);
arr2[1] = arr.splice(0, arr.length);    //[[1, 2], [3, 4]]

//create a function that produces matches in a round from array[i]
function round (arr2) {
  for (var i = 0; i < arr2[0].length; i++){
      arr4.push([arr2[0][i], arr2[1][i]]);
  }
 arr2 = arr4;
 return arr2; // [[1 v 3], [2 v 4]] etc.
}
//create a function that tranforms the arr to gameweek +1 (rotate everything clockwise apart from team 1
function trans(arr2){
  //create new arr5 that is the same as arr2
  arr5 = [[],[]];
  for (var i = 0; i < arr2[0].length; i++) {
    arr5[0].push(arr2[0][i])
    arr5[1].push(arr2[1][i])
   }

   //rotate every element apart from arr2[0,0] : [[1, 3], [4, 2]]
  let h = arr2[0].length - 1;
  arr2[0][1] = arr5[1][0];
  arr2[1][h] = arr5[0][h];
  for (var i = 2; i <= h; i++){
  arr2[0][i] = arr5[0][i-1];} 
  for (var i = 0; i <= h-1; i++){
  arr2[1][i] = arr5[1][i+1];}
  return arr2;
}

function final (n, arr2, arr3){ //putting all the functions together
  for (var i = 0; i < n-1; i++){
    arr3[i] = (round(arr2));
    trans(arr2);
  }
  return arr3; // [[1, 3], [2, 4, [1, 4], [3, 2], [1, 2], [4, 3]] X 3
}

final(n, arr2, arr3)
let arr6 = arr3[0]; // arr6 = [[1, 3], [2, 4, [1, 4], [3, 2], [1, 2], [4, 3]]

function cut(arr6, n) {
  let arr7 = [];
  let index = 0;
  while (index < arr6.length) {
    arr7.push(arr6.slice(index, n/2+index));
    index += n/2;
  }
  return arr7;
}

cut(arr6, n); 

console.log(n);
console.log(arr);
console.log(arr2);
console.log(arr3[0]);
console.log(arr4);
console.log(arr6);
console.log(arr7);//not working!
//return arr7
}
buildMatchesTable(6)

Answer 1

难怪，您在函数内声明let arr7 = [];。将其从函数中取出，与 arr6、arr4 等处于同一级别。