PHP Class&Object -- In-depth analysis of PHP self-sorting binary trees_PHP tutorial

By applying some sorting logic between nodes, a binary tree can provide an excellent way to organize it. For each node, have elements that satisfy all specified conditions be located at the left node and its children. When inserting a new element, we need to start from the first node (root node) of the tree, determine which side of the node it belongs to, and then find the appropriate position along this side. Similarly, when reading data, Just use the in-order traversal method to traverse the binary tree.

Copy code The code is as follows:

ob_start();
// Here we need to include the binary tree class
Class Binary_Tree_Node() {
   // You can find the details at
}
ob_end_clean();
// Define a class to implement self sorting binary tree
class Sorting_Tree {
    // Define the variable to hold our tree:
    public $tree;
    // We need a method that will allow for inserts that automatically place
    // themselves in the proper order in the tree
    public function insert($val) {
        // Handle the first case:
        if (!(isset($this->tree))) {
            $this->tree = new Binary_Tree_Node($val);
        } else {
            // In all other cases:
            // Start a pointer that looks at the current tree top:
            $pointer = $this->tree;
            // Iteratively search the tree for the right place:
            for(;;) {
                // If this value is less than, or equal to the current data:
                if ($val <= $pointer->data) {
                    // We are looking to the left ... If the child exists:
                    if ($pointer->left) {
                        // Traverse deeper:
                        $pointer = $pointer->left;
                    } else {
                        // Found the new spot: insert the new element here:
                        $pointer->left = new Binary_Tree_Node($val);
                        break;
                    }
                } else {
                    // We are looking to the right ... If the child exists:
                    if ($pointer->right) {
                        // Traverse deeper:
                        $pointer = $pointer->right;
                    } else {
                        // Found the new spot: insert the new element here:
                        $pointer->right = new Binary_Tree_Node($val);
                        break;
                    }
                }
            }
        }
    }

    // Now create a method to return the sorted values of this tree.
    // All it entails is using the in-order traversal, which will now
    // give us the proper sorted order.
    public function returnSorted() {
        return $this->tree->traverseInorder();
    }
}
// Declare a new sorting tree:
$sort_as_you_go = new Sorting_Tree();
// Let's randomly create 20 numbers, inserting them as we go:
for ($i = 0; $i < 20; $i++) {
    $sort_as_you_go->insert(rand(1,100));
}
// Now echo the tree out, using in-order traversal, and it will be sorted:
// Example: 1, 2, 11, 18, 22, 26, 32, 32, 34, 43, 46, 47, 47, 53, 60, 71,
//   75, 84, 86, 90
echo '

', implode(', ', $sort_as_you_go->returnSorted()), '

';
?>

http://www.bkjia.com/PHPjc/327866.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/327866.htmlTechArticle在节点之间再应用一些排序逻辑，二叉树就能提供出色的组织方式。对于每个节点，都让满足所有特定条件的元素都位于左节点及其子节点...