如何将扁平的章节数组转换成嵌套的树形结构？

const chapters = [{
  level: '1',
  content: '案例概况010000-170900',
  url: '案例概况010000-170900.html'
},{
  level: '2',
  content: '案例概况010100-170901',
  url: '案例概况010100-170901.html'
},{
  level: '2',
  content: '案例概况010200-170902',
  url: '案例概况010200-170902.html'
},{
  level: '3',
  content: '案例概况010201-170903',
  url: '案例概况010201-170903.html'
},{
  level: '1',
  content: '案例概况020000-170904',
  url: '案例概况020000-170904.html'
},{
  level: '1',
  content: '案例概况030000-170905',
  url: '案例概况030000-170905.html'
},{
  level: '2',
  content: '案例概况030100-170906',
  url: '案例概况030100-170906.html'
}];

const tree = [{
  level: '1',
  content: '案例概况010000-170900',
  url: '案例概况010000-170900.html',
  childs: [{
    level: '2',
    content: '案例概况010100-170901',
    url: '案例概况010100-170901.html',
    childs: []
  },{
    level: '2',
    content: '案例概况010200-170902',
    url: '案例概况010200-170902.html',
    childs: [{
      level: '3',
      content: '案例概况010201-170903',
      url: '案例概况010201-170903.html',
      childs: []
    }]
  }]
},{
  level: '1',
  content: '案例概况020000-170904',
  url: '案例概况020000-170904.html',
  childs: []
},{
  level: '1',
  content: '案例概况030000-170905',
  url: '案例概况030000-170905.html',
  childs: [{
    level: '2',
    content: '案例概况030100-170906',
    url: '案例概况030100-170906.html',
    childs: []
  }]
}];

function convertToTree(chapters) {
  // 按照 level 排序
  chapters.sort((a, b) => parseInt(a.level) - parseInt(b.level));

  const tree = [];
  const map = new Map(); // 使用 Map 提高查找效率

  chapters.forEach(chapter => {
    const level = parseInt(chapter.level);
    if (level === 1) {
      tree.push({ ...chapter, childs: [] });
      map.set(chapter.content, tree[tree.length - 1]);
    } else {
      let parent = findParent(map, chapter);
      if (parent) {
        parent.childs.push({ ...chapter, childs: [] });
        map.set(chapter.content, parent.childs[parent.childs.length - 1]);
      }
    }
  });

  return tree;
}

function findParent(map, chapter) {
  let level = parseInt(chapter.level);
  let parentContent = chapter.content.substring(0, chapter.content.length - 2); // 假设父节点的content是子节点content的前缀，需要根据实际情况调整
  while (level > 1) {
    if (map.has(parentContent)) {
      return map.get(parentContent);
    }
    level--;
    parentContent = parentContent.substring(0, parentContent.length - 2);
  }
  return null;
}

const tree = convertToTree(chapters);
console.log(JSON.stringify(tree, null, 2));