怎么使用JavaScript实现红黑树？

可以使用以下步骤来实现红黑树：

1. 定义节点结构体，包括键值、左右子节点、父节点、颜色等属性。
2. 定义红黑树类，包括插入、删除、查找等方法。
3. 实现插入方法，首先按照二叉搜索树的方式插入节点，然后根据红黑树的规则进行颜色调整和旋转操作，使得树保持平衡。
4. 实现删除方法，首先按照二叉搜索树的方式删除节点，然后根据红黑树的规则进行颜色调整和旋转操作，使得树保持平衡。
5. 实现查找方法，按照二叉搜索树的方式查找节点。

以下是 JavaScript 实现红黑树的示例代码：

class Node {
  constructor(key) {
    this.key = key;
    this.left = null;
    this.right = null;
    this.parent = null;
    this.color = 'red';
  }
}

class RedBlackTree {
  constructor() {
    this.root = null;
  }

  insert(key) {
    const node = new Node(key);
    if (!this.root) {
      this.root = node;
      this.root.color = 'black';
      return;
    }

    let current = this.root;
    while (current) {
      if (key < current.key) {
        if (!current.left) {
          current.left = node;
          node.parent = current;
          break;
        }
        current = current.left;
      } else {
        if (!current.right) {
          current.right = node;
          node.parent = current;
          break;
        }
        current = current.right;
      }
    }

    this.fixInsert(node);
  }

  fixInsert(node) {
    while (node.parent && node.parent.color === 'red') {
      if (node.parent === node.parent.parent.left) {
        const uncle = node.parent.parent.right;
        if (uncle && uncle.color === 'red') {
          node.parent.color = 'black';
          uncle.color = 'black';
          node.parent.parent.color = 'red';
          node = node.parent.parent;
        } else {
          if (node === node.parent.right) {
            node = node.parent;
            this.rotateLeft(node);
          }
          node.parent.color = 'black';
          node.parent.parent.color = 'red';
          this.rotateRight(node.parent.parent);
        }
      } else {
        const uncle = node.parent.parent.left;
        if (uncle && uncle.color === 'red') {
          node.parent.color = 'black';
          uncle.color = 'black';
          node.parent.parent.color = 'red';
          node = node.parent.parent;
        } else {
          if (node === node.parent.left) {
            node = node.parent;
            this.rotateRight(node);
          }
          node.parent.color = 'black';
          node.parent.parent.color = 'red';
          this.rotateLeft(node.parent.parent);
        }
      }
    }
    this.root.color = 'black';
  }

  delete(key) {
    const node = this.search(key);
    if (!node) {
      return;
    }

    let child;
    if (!node.left || !node.right) {
      child = node.left || node.right;
    } else {
      const successor = this.successor(node);
      node.key = successor.key;
      node.color = successor.color;
      node.left = successor.left;
      node.right = successor.right;
      child = successor.left || successor.right;
    }

    if (child) {
      child.parent = node.parent;
    }

    if (!node.parent) {
      this.root = child;
    } else if (node === node.parent.left) {
      node.parent.left = child;
    } else {
      node.parent.right = child;
    }

    if (node.color === 'black') {
      this.fixDelete(child, node.parent);
    }
  }

  fixDelete(node, parent) {
    while (node !== this.root && (!node || node.color === 'black')) {
      if (node === parent.left) {
        let sibling = parent.right;
        if (sibling.color === 'red') {
          sibling.color = 'black';
          parent.color = 'red';
          this.rotateLeft(parent);
          sibling = parent.right;
        }
        if ((!sibling.left || sibling.left.color === 'black') && (!sibling.right || sibling.right.color === 'black')) {
          sibling.color = 'red';
          node = parent;
          parent = node.parent;
        } else {
          if (!sibling.right || sibling.right.color === 'black') {
            sibling.left.color = 'black';
            sibling.color = 'red';
            this.rotateRight(sibling);
            sibling = parent.right;
          }
          sibling.color = parent.color;
          parent.color = 'black';
          sibling.right.color = 'black';
          this.rotateLeft(parent);
          node = this.root;
        }
      } else {
        let sibling = parent.left;
        if (sibling.color === 'red') {
          sibling.color = 'black';
          parent.color = 'red';
          this.rotateRight(parent);
          sibling = parent.left;
        }
        if ((!sibling.left || sibling.left.color === 'black') && (!sibling.right || sibling.right.color === 'black')) {
          sibling.color = 'red';
          node = parent;
          parent = node.parent;
        } else {
          if (!sibling.left || sibling.left.color === 'black') {
            sibling.right.color = 'black';
            sibling.color = 'red';
            this.rotateLeft(sibling);
            sibling = parent.left;
          }
          sibling.color = parent.color;
          parent.color = 'black';
          sibling.left.color = 'black';
          this.rotateRight(parent);
          node = this.root;
        }
      }
    }
    if (node) {
      node.color = 'black';
    }
  }

  search(key) {
    let current = this.root;
    while (current) {
      if (key === current.key) {
        return current;
      } else if (key < current.key) {
        current = current.left;
      } else {
        current = current.right;
      }
    }
    return null;
  }

  successor(node) {
    if (node.right) {
      let current = node.right;
      while (current.left) {
        current = current.left;
      }
      return current;
    } else {
      let current = node.parent;
      while (current && node === current.right) {
        node = current;
        current = current.parent;
      }
      return current;
    }
  }

  rotateLeft(node) {
    const right = node.right;
    node.right = right.left;
    if (right.left) {
      right.left.parent = node;
    }
    right.parent = node.parent;
    if (!node.parent) {
      this.root = right;
    } else if (node === node.parent.left) {
      node.parent.left = right;
    } else {
      node.parent.right = right;
    }
    right.left = node;
    node.parent = right;
  }

  rotateRight(node) {
    const left = node.left;
    node.left = left.right;
    if (left.right) {
      left.right.parent = node;
    }
    left.parent = node.parent;
    if (!node.parent) {
      this.root = left;
    } else if (node === node.parent.right) {
      node.parent.right = left;
    } else {
      node.parent.left = left;
    }
    left.right = node;
    node.parent = left;
  }
}

注意：这只是一个简单的实现，可能存在性能问题和 bug，仅供参考。