Question

我需要在PHP中实现“完美的二叉树”。

目前，我有这个：

<?php
   $teams = 8;
   $num_rounds = round(log($teams, 2)) + 1;

   for ($i = 0; $i < $num_rounds; ++$i)
   {
    $matches = $teams * pow(.5, $i - 1) / 2;
    for ($j = 0; $j < $matches; ++$j)
    {
     echo "<div style=\"border-style: inset;\"><span>Round $i Match $j</span></div>\n";
    }
   }
?>

您可以查看here。我正在使用Frank Mich jQuery Binary Tree插件来显示数据，但正如我之前所说，我认为我需要一个二叉树才能正确显示它。

如果有更好的方法，或者我只是做错了？解决方案是什么？

Answer 1

这是在php中实现二叉树（数据结构）的代码：

<?php
class Node
{
    public $data;
    public $leftChild;
    public $rightChild;

    public function __construct($data)
    {
        $this->data = $data;
        $this->leftChild = null;
        $this->rightChild = null;
    }

    public function disp_data()
    {
        echo $this->data;
    }
}

class BinaryTree
{
    public $root;

    public function __construct()
    {
        $this->root = null;
    }

    /**
     * function to display the tree
     */
    public function display()
    {
        $this->display_tree($this->root);
    }

    public function display_tree($local_root)
    {
        if ($local_root == null) {
            return;
        }
        $this->display_tree($local_root->leftChild);
        echo $local_root->data."<br/>";
        $this->display_tree($local_root->rightChild);
    }

    /**
     * function to insert a new node
     */
    public function insert($key)
    {
        $newnode = new Node($key);
        if ($this->root == null) {
            $this->root = $newnode;

            return;
        } else {
            $parent = $this->root;
            $current = $this->root;
            while (true) {
                $parent = $current;
                if ($key == ($this->find_order($key, $current->data))) {
                    $current = $current->leftChild;
                    if ($current == null) {
                        $parent->leftChild = $newnode;

                        return;
                    }//end if2
                } else {
                    $current = $current->rightChild;
                    if ($current == null) {
                        $parent->rightChild = $newnode;

                        return;
                    }
                }
            }
        }
    }

    /**
     * function to search a particular Node
     */
    public function find($key)
    {
        $current = $this->root;
        while ($current->data != $key) {
            if ($key == $this->find_order($key, $current->data)) {
                $current = $current->leftChild;
            } else {
                $current = $current->rightChild;
            }
            if ($current == null) {
                return (null);
            }
        }

        return ($current->data);
    }

    public function delete1($key)
    {
        $current = $this->root;
        $parent = $this->root;

        $isLeftChild = true;
        while ($current->data != $key) {
            $parent = $current;
            if ($key == ($this->find_order($key, $current->data))) {
                $current = $current->leftChild;
                $isLeftChild = true;
            } else {
                $current = $current->rightChild;
                $isLeftChild = false;
            }
            if ($current == null) {
                return (null);
            }
        }

        echo "<br/><br/>Node to delete:".$current->data;
        //to delete a leaf node
        if ($current->leftChild == null && $current->rightChild == null) {
            if ($current == $this->root) {
                $this->root = null;
            } else {
                if ($isLeftChild == true) {
                    $parent->leftChild = null;
                } else {
                    $parent->rightChild = null;
                }
            }

            return ($current);
        } else { //to delete a node having a leftChild
            if ($current->rightChild == null) {
                if ($current == $this->root) {
                    $this->root = $current->leftChild;
                } else {
                    if ($isLeftChild == true) {
                        $parent->leftChild = $current->leftChild;
                    } else {
                        $parent->rightChild = $current->leftChild;
                    }
                }

                return ($current);
            } else { //to delete a node having a rightChild
                if ($current->leftChild == null) {
                    if ($current == $this->root) {
                        $this->root = $current->rightChild;
                    } else {
                        if ($isLeftChild == true) {
                            $parent->leftChild = $current->rightChild;
                        } else {
                            $parent->rightChild = $current->rightChild;
                        }
                    }

                    return ($current);
                } else { //to delete a node having both childs
                    $successor = $this->get_successor($current);
                    if ($current == $this->root) {
                        $this->root = $successor;
                    } else {
                        if ($isLeftChild == true) {
                            $parent->leftChild = $successor;
                        } else {
                            $parent->rightChild = $successor;
                        }
                    }
                    $successor->leftChild = $current->leftChild;

                    return ($current);
                }
            }
        }
    }

    /**
     * Function to find the successor node
     */
    public function get_successor($delNode)
    {
        $succParent = $delNode;
        $successor = $delNode;
        $temp = $delNode->rightChild;
        while ($temp != null) {
            $succParent = $successor;
            $successor = $temp;
            $temp = $temp->leftChild;
        }

        if ($successor != $delNode->rightChild) {
            $succParent->leftChild = $successor->rightChild;
            $successor->rightChild = $delNode->rightChild;
        }

        return ($successor);
    }

    /**
     * function to find the order of two strings
     */
    public function find_order($str1, $str2)
    {
        $str1 = strtolower($str1);
        $str2 = strtolower($str2);
        $i = 0;
        $j = 0;

        $p1 = $str1[$i];
        $p2 = $str2[$j];
        while (true) {
            if (ord($p1) < ord($p2) || ($p1 == '' && $p2 == '')) {
                return ($str1);
            } else {
                if (ord($p1) == ord($p2)) {
                    $p1 = $str1[++$i];
                    $p2 = $str2[++$j];
                    continue;
                }

                return ($str2);
            }
        }
    }

    public function is_empty()
    {
        return $this->root === null;
    }
}

Answer 2

从Frank Mich Binary Tree page开始，您的树条目将显示如下：

0
  \
    1
  /   \
2      \
        \
          3
        /   \
4      /     \
  \   /       \
    5          \
  /             \
6                \
                  \
                    7
                  /
8                /
  \             /
    9          /
  /   \       /
10     \     /
        \   /
          11
        /
12     /
  \   /
    13
  /
14

树中的每个数字表示输入数组中其条目的索引。请注意，倒计时第一轮，索引上升2.在第二列中，它们上升4，第三列上升8。

我会创建一个包含每个游戏名称的字符串数组。然后做这样的事情：

num_rounds = x
num_games = (2 ^ num_rounds) - 1
game_names = array(num_games)
for round = 0 to num_rounds - 1
    index = (2 ^ round) - 1
    increment = 2 ^ (round + 1)
    game_number = 0
    while index < num_games
        game_names[index] = sprintf("round %s, game %s", round, game_number)
        game_number++
        index += increment
display_tree(game_names)

PHP二进制树实现

2 个答案: