\u7ee7\u7eed\u4e0a\u4e00\u7bc7\u7684\u5185\u5bb9\uff0c\u8fd9\u6b21\u662f\u5728\u4e8c\u53c9\u6811\u7684\u57fa\u7840\u4e0a\u6dfb\u52a0\u4e8c\u53c9\u641c\u7d22\u6811\u7684\u67e5\u627e\u3001\u63d2\u5165\u548c\u5220\u9664\u65b9\u6cd5\u3002<\/p>\n\n\n\n
<?php\n\n\/**\n * \u8282\u70b9\u7c7b\n *\/\nclass TreeNode\n{\n\n private ?self $left = null;\n\n private ?self $right = null;\n\n private int $value;\n\n private ?self $parent;\n\n public function __construct(int $value, self $parent = null)\n {\n $this->value = $value;\n $this->parent = $parent;\n }\n\n \/**\n * @return int\n *\/\n public function getValue(): int\n {\n return $this->value;\n }\n\n \/**\n * @return self|null\n *\/\n public function getLeft(): ?self\n {\n return $this->left;\n }\n\n \/**\n * @return self|null\n *\/\n public function getRight(): ?self\n {\n return $this->right;\n }\n\n \/**\n * @param self|null $left\n *\/\n public function setLeft(?self $left): void\n {\n $this->left = $left;\n }\n\n \/**\n * @param self|null $right\n *\/\n public function setRight(?self $right): void\n {\n $this->right = $right;\n }\n\n \/**\n * @return self|null\n *\/\n public function getParent(): ?self\n {\n return $this->parent;\n }\n\n \/**\n * @param self $parent\n *\/\n public function setParent(self $parent): void\n {\n $this->parent = $parent;\n }\n\n \/**\n * @param int $value\n *\/\n public function setValue(int $value): void\n {\n $this->value = $value;\n }\n}\n\n\/**\n * \u6811\n *\/\nclass Tree\n{\n\n protected ?TreeNode $root;\n\n public function __construct(array $dataSet1, array $dataSet2, string $method)\n {\n switch ($method) {\n case 'pre': \/\/ \u6839\u636e\u524d\u5e8f\u548c\u4e2d\u5e8f\u904d\u5386\u7684\u7ed3\u679c\u6784\u5efa\n $this->root = $this->makeFromPreOrderAndInOrder($dataSet1, $dataSet2);\n break;\n case 'post':\/\/ \u6839\u636e\u540e\u5e8f\u548c\u4e2d\u5e8f\u904d\u5386\u7684\u7ed3\u679c\u6784\u5efa\n $this->root = $this->makeFromPostOrderAndInOrder($dataSet1, $dataSet2);\n break;\n default:\n throw new InvalidArgumentException;\n }\n }\n\n \/**\n * \u4ece\u524d\u5e8f\u904d\u5386\u548c\u4e2d\u5e8f\u904d\u5386\u7684\u7ed3\u679c\u6784\u5efa\u539f\u6765\u7684\u6811\n * \u89e3\u6cd5\uff1a\u5148\u5e8f\u4e2d\u7684\u9996\u5143\u7d20a \u5fc5\u4e3a\u8be5\u4e8c\u53c9\u6811\u7684\u6839\u7ed3\u70b9\uff0c\u5728\u4e2d\u5e8f\u5e8f\u5217\u91cca\u4e4b\u524d\u7684\u5143\u7d20\u4e00\u5b9a\u662fa\u7684\u5de6\u5b50\u6811\u90e8\u5206\uff0ca\u4e4b\u540e\u7684\u5143\u7d20\u4e00\u5b9a\u4e3aa\u7684\u53f3\u5b50\u6811\u90e8\u5206\u3002\n *\n * @param int[] $pre\n * @param int[] $in\n * @param TreeNode|null $parent\n * @return TreeNode\n *\/\n public function makeFromPreOrderAndInOrder(array $pre, array $in, TreeNode $parent = null): TreeNode\n {\n $currentRoot = $pre[0]; \/\/ \u524d\u5e8f\u904d\u5386\u7684\u9996\u5143\u7d20\u80af\u5b9a\u662f\u6839\u8282\u70b9\n $currentRootPos = array_search($currentRoot, $in, true);\n $left = array_slice($in, 0, $currentRootPos);\n $right = array_slice($in, $currentRootPos + 1);\n $preLeft = array_slice($pre, 1, $currentRootPos);\n $preRight = array_slice($pre, $currentRootPos + 1);\n $currentRoot = new TreeNode($currentRoot, $parent);\n\n if ($left) {\n $currentRoot->setLeft($this->makeFromPreOrderAndInOrder($preLeft, $left, $currentRoot));\n }\n\n if ($right) {\n $currentRoot->setRight($this->makeFromPreOrderAndInOrder($preRight, $right, $currentRoot));\n }\n\n return $currentRoot;\n }\n\n \/**\n * \u4ece\u540e\u5e8f\u904d\u5386\u548c\u4e2d\u5e8f\u904d\u5386\u7684\u7ed3\u679c\u91cd\u65b0\u6784\u5efa\u6811\n * \u601d\u8def\u540c\u4e0a\uff0c\u53ea\u662f\u53cd\u4e86\u8fc7\u6765\n *\n * @param array $post\n * @param array $in\n * @param TreeNode|null $parent\n * @return TreeNode\n *\/\n public function makeFromPostOrderAndInOrder(array $post, array $in, TreeNode $parent = null): TreeNode\n {\n $currentRoot = $post[count($post) - 1]; \/\/ \u540e\u5e8f\u904d\u5386\u7684\u6700\u540e\u4e00\u4e2a\u5143\u7d20\u662f\u6839\u8282\u70b9\n $currentRootPos = array_search($currentRoot, $in, true);\n $left = array_slice($in, 0, $currentRootPos);\n $right = array_slice($in, $currentRootPos + 1);\n $postLeft = array_slice($post, 0, $currentRootPos);\n $postRight = array_slice($post, $currentRootPos, -1);\n\n $currentRoot = new TreeNode($currentRoot, $parent);\n\n if ($left) {\n $currentRoot->setLeft($this->makeFromPostOrderAndInOrder($postLeft, $left, $currentRoot));\n }\n\n if ($right) {\n $currentRoot->setRight($this->makeFromPostOrderAndInOrder($postRight, $right, $currentRoot));\n }\n\n return $currentRoot;\n }\n\n \/**\n * \u524d\u5e8f\u904d\u5386\n *\n * @param TreeNode|null $treeNode\n * @return array\n *\/\n public function preOrderTraversal(TreeNode $treeNode = null): array\n {\n if (is_null($treeNode)) {\n $treeNode = $this->root;\n }\n\n $ret = [];\n\n $ret[] = $treeNode->getValue(); \/\/ \u8282\u70b9\u9a6c\u4e0a\u8f93\u51fa\n\n if ($treeNode->getLeft()) {\n $ret = array_merge($ret, $this->preOrderTraversal($treeNode->getLeft()));\n }\n if ($treeNode->getRight()) {\n $ret = array_merge($ret, $this->preOrderTraversal($treeNode->getRight()));\n }\n\n return $ret;\n }\n\n \/**\n * \u4e2d\u5e8f\u904d\u5386\n *\n * @param TreeNode $treeNode\n * @return array\n *\/\n public function inOrderTraversal(TreeNode $treeNode = null): array\n {\n if (is_null($treeNode)) {\n $treeNode = $this->root;\n }\n\n $ret = [];\n\n if ($treeNode->getLeft()) {\n $ret = array_merge($ret, $this->inOrderTraversal($treeNode->getLeft()));\n }\n\n $ret[] = $treeNode->getValue(); \/\/\u53ea\u6709\u5f53\u904d\u5386\u5b8c\u5de6\u8282\u70b9\u540e\u624d\u8f93\u51fa\n\n if ($treeNode->getRight()) {\n $ret = array_merge($ret, $this->inOrderTraversal($treeNode->getRight()));\n }\n\n return $ret;\n }\n\n \/**\n * \u540e\u5e8f\u904d\u5386\n *\n * @param TreeNode|null $treeNode\n * @return array\n *\/\n public function postOrderTraversal(TreeNode $treeNode = null): array\n {\n if (is_null($treeNode)) {\n $treeNode = $this->root;\n }\n\n $ret = [];\n\n if ($treeNode->getLeft()) {\n $ret = array_merge($ret, $this->postOrderTraversal($treeNode->getLeft()));\n }\n\n if ($treeNode->getRight()) {\n $ret = array_merge($ret, $this->postOrderTraversal($treeNode->getRight()));\n }\n\n $ret[] = $treeNode->getValue(); \/\/ \u904d\u5386\u5b8c\u5de6\u53f3\u8282\u70b9\u540e\u624d\u8f93\u51fa\n\n return $ret;\n }\n}\n\nclass BinSearchTree extends Tree\n{\n\n \/**\n * \u63d2\u5165\n *\n * @param int $value\n * @param TreeNode|null $treeNode\n *\/\n public function insert(int $value, TreeNode $treeNode = null)\n {\n if (is_null($treeNode)) {\n $treeNode = $this->root;\n }\n if ($treeNode->getValue() > $value) {\n if ($treeNode->getLeft()) {\n $this->insert($value, $treeNode->getLeft());\n } else {\n $treeNode->setLeft(new TreeNode($value,$treeNode));\n }\n } else {\n if ($treeNode->getRight()) {\n $this->insert($value, $treeNode->getRight());\n } else {\n $treeNode->setRight(new TreeNode($value,$treeNode));\n }\n }\n }\n\n \/**\n * \u641c\u7d22\n *\n * @param int $value\n * @param TreeNode|null $treeNode\n * @return TreeNode|null\n *\/\n public function search(int $value, TreeNode $treeNode = null): ?TreeNode\n {\n if (is_null($treeNode)) {\n $treeNode = $this->root;\n }\n $nodeValue = $treeNode->getValue();\n if ($nodeValue === $value) {\n return $treeNode;\n }\n if ($nodeValue > $value && !is_null($treeNode->getLeft())) { \/\/ \u5728\u5de6\u5b50\u6811\u7ee7\u7eed\u627e\n return $this->search($value, $treeNode->getLeft());\n }\n\n if ($nodeValue < $value && !is_null($treeNode->getRight())) { \/\/ \u5728\u53f3\u5b50\u6811\u7ee7\u7eed\u627e\n return $this->search($value, $treeNode->getRight());\n }\n\n return null; \/\/ \u6ca1\u6709\u627e\u5230\n }\n\n public function delete(int $value, TreeNode $treeNode=null): bool\n {\n $find=$this->search($value);\n\n if(is_null($find)){\n return false;\n }\n\n $findValue=$find->getValue();\n $parent=$find->getParent();\n $parentValue=is_null($parent)?null:$parent->getValue();\n\n \/\/ \u8be5\u8282\u70b9\u6ca1\u6709\u5b50\u8282\u70b9\uff0c\u76f4\u63a5\u5220\u9664\uff0c\u5373\u5728\u7236\u8282\u70b9\u5c06\u8be5\u8282\u70b9\u8bbe\u4e3a null\n if(is_null($find->getLeft()) && is_null($find->getRight())){\n if(is_null($parent)){\/\/ \u53ea\u6709\u4e00\u4e2a\u6839\u8282\u70b9\n $this->root=null;\n }else{\n if($parentValue>$findValue){ \/\/ \u7236\u8282\u70b9\u503c\u5927\u4e8e\u5b50\u8282\u70b9\uff0c\u5373\u5b50\u8282\u70b9\u5728\u7236\u8282\u70b9\u5de6\u5b50\u6811\u4e0a\n $parent->setLeft(null);\n }else{\n $parent->setRight(null);\n }\n }\n\n }\n\n \/\/ \u53ea\u6709\u5de6\u8282\u70b9\uff0c\u628a\u7236\u8282\u70b9\u6307\u5411\u5de6\u8282\u70b9\n if(!is_null($find->getLeft()) && is_null($find->getRight())){\n if(is_null($parent)){ \/\/ \u8981\u5220\u9664\u7684\u8282\u70b9\u662f\u6839\u8282\u70b9\uff0c\u76f4\u63a5\u628a\u6811\u7684\u6839\u8282\u70b9\u6307\u5411\u5de6\u5b50\u6811\n $this->root=$find->getLeft();\n }else{\n if($parentValue>$findValue){\n $parent->setLeft($find->getLeft());\n }else{\n $parent->setRight($find->getLeft());\n }\n }\n }\n\n \/\/ \u53ea\u6709\u53f3\u8282\u70b9\uff0c\u540c\u4e0a\u5904\u7406\n if(is_null($find->getLeft()) && !is_null($find->getRight())){\n if(is_null($parent)){\n $this->root=$find->getRight();\n }else{\n if($parentValue>$findValue){\n $parent->setLeft($find->getRight());\n }else{\n $parent->setRight($find->getRight());\n }\n }\n\n }\n\n \/\/ \u6709\u5de6\u53f3\u8282\u70b9\uff0c\u627e\u5230\u53f3\u5b50\u6811\u6700\u5de6\u8282\u70b9\uff0c\u5373\u6700\u5c0f\u5143\u7d20\uff08\u4e2d\u5e8f\u904d\u5386\u7b2c\u4e00\u4e2a\u5143\u7d20\uff09\uff0c\u8fdb\u884c\u66ff\u6362\u5220\u9664\n \/\/ \u8fd9\u6837\u505a\u662f\u56e0\u4e3a\u5bf9\u6574\u68f5\u6811\u5f71\u54cd\u6700\u5c0f\uff1f\n if(!is_null($find->getLeft()) && !is_null($find->getRight())){\n $inOrderResult=$this->inOrderTraversal($find->getRight());\n $min=$this->search($inOrderResult[0],$find->getRight());\n $minValue=$min->getValue();\n $this->delete($minValue); \/\/ \u5220\u9664\u53f3\u5b50\u6811\u6700\u5c0f\u5143\u7d20\n $find->setValue($minValue); \/\/ \u8981\u5220\u9664\u7684\u5143\u7d20\u66ff\u6362\u4e3a\u53f3\u5b50\u6811\u6700\u5c0f\u5143\u7d20\n }\n\n return true;\n }\n}\n\n\n$pre = [8, 3, 1, 6, 4, 7, 10, 14, 13];\n$in = [1, 3, 4, 6, 7, 8, 10, 13, 14];\n\n$tree = new BinSearchTree($pre, $in, 'pre');\n\n$tree->insert(2);\n\n$n2=$tree->search(2);\necho $n2->getParent()->getValue(),PHP_EOL;\n\n$tree->delete(8);\n\nvar_export($tree->preOrderTraversal());\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"\u7ee7\u7eed\u4e0a\u4e00\u7bc7\u7684\u5185\u5bb9\uff0c\u8fd9\u6b21\u662f\u5728\u4e8c\u53c9\u6811\u7684\u57fa\u7840\u4e0a\u6dfb\u52a0\u4e8c\u53c9\u641c\u7d22\u6811\u7684\u67e5\u627e\u3001\u63d2\u5165\u548c\u5220\u9664\u65b9\u6cd5\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[179],"tags":[186,196],"class_list":["post-328","post","type-post","status-publish","format-standard","hentry","category-notes","tag-php","tag-196"],"_links":{"self":[{"href":"https:\/\/www.gwlin.com\/blog\/wp-json\/wp\/v2\/posts\/328","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gwlin.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gwlin.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gwlin.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gwlin.com\/blog\/wp-json\/wp\/v2\/comments?post=328"}],"version-history":[{"count":0,"href":"https:\/\/www.gwlin.com\/blog\/wp-json\/wp\/v2\/posts\/328\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.gwlin.com\/blog\/wp-json\/wp\/v2\/media?parent=328"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gwlin.com\/blog\/wp-json\/wp\/v2\/categories?post=328"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gwlin.com\/blog\/wp-json\/wp\/v2\/tags?post=328"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}