Commit 46541b82 authored by Margatroid's avatar Margatroid
Browse files

Merge branch 'llrbt' of https://github.com/Enter-tainer/OI-wiki into llrbt

parents 9d5d23e4 97c7a3f3

docs/ds/llrbt.md

+39 −34
Original line number Diff line number Diff line
@@ -60,11 +60,12 @@ 
??? note "参考代码（部分）"

    ```cpp

    template <class Key, class Compare>

    typename Set<Key, Compare>::Node *

    Set<Key, Compare>::fix_up(Set::Node *root) const {

    typename Set<Key, Compare>::Node *Set<Key, Compare>::fix_up(

        Set::Node *root) const {

      if (is_red(root->rc) && !is_red(root->lc))  // fix right leaned red link

        root = rotate_left(root);

      if (is_red(root->lc) && is_red(root->lc->lc)) // fix doubly linked left leaned red link

      if (is_red(root->lc) &&

          is_red(root->lc->lc))  // fix doubly linked left leaned red link

        // if (root->lc == nullptr), then the second expr won't be evaluated

        root = rotate_right(root);

      if (is_red(root->lc) && is_red(root->rc))
@@ -73,6 +74,7 @@ 
      root->size = size(root->lc) + size(root->rc) + 1;

      return root;

    }

    ```



    template<class Key, class Compare>

    typename Set<Key, Compare>::Node *
@@ -117,8 +119,8 @@ 
??? note "参考代码（部分）"

    ```cpp

    template <class Key, class Compare>

    typename Set<Key, Compare>::Node *

    Set<Key, Compare>::move_red_left(Set::Node *root) const {

    typename Set<Key, Compare>::Node *Set<Key, Compare>::move_red_left(

        Set::Node *root) const {

      color_flip(root);

      if (is_red(root->rc->lc)) {

        // assume that root->rc != nullptr when calling this function
@@ -128,6 +130,7 @@ 
      }

      return root;

    }

    ```



    template<class Key, class Compare>

    typename Set<Key, Compare>::Node *
@@ -160,25 +163,25 @@ 
??? note "参考代码（部分）"

    ```cpp

    template <class Key, class Compare>

    typename Set<Key, Compare>::Node *

    Set<Key, Compare>::delete_arbitrary(Set::Node *root, Key key) const {

    typename Set<Key, Compare>::Node *Set<Key, Compare>::delete_arbitrary(

        Set::Node *root, Key key) const {

      if (cmp_(key, root->key)) {

        // key < root->key

        if (!is_red(root->lc) && !(is_red(root->lc->lc)))

          root = move_red_left(root);

        // ensure the invariant: either root->lc or root->lc->lc (or root and root->lc after dive into the function) is red,

        // to ensure we will eventually delete a red node. therefore we will not break the black height balance

        // ensure the invariant: either root->lc or root->lc->lc (or root and

        // root->lc after dive into the function) is red, to ensure we will

        // eventually delete a red node. therefore we will not break the black

        // height balance

        root->lc = delete_arbitrary(root->lc, key);

      } else {

        // key >= root->key

        if (is_red(root->lc))

          root = rotate_right(root);

        if (is_red(root->lc)) root = rotate_right(root);

        if (key == root->key && root->rc == nullptr) {

          delete root;

          return nullptr;

        }

        if (!is_red(root->rc) && !is_red(root->rc->lc))

          root = move_red_right(root);

        if (!is_red(root->rc) && !is_red(root->rc->lc)) root = move_red_right(root);

        if (key == root->key) {

          root->key = get_min(root->rc);

          root->rc = delete_min(root->rc);
@@ -187,6 +190,7 @@ 
        }

      }

      return fix_up(root);

    ```



    }

    ```
@@ -200,6 +204,7 @@ 
    #include <algorithm>

    #include <memory>

    #include <vector>

    ```



    template<class Key, class Compare = std::less<Key>>

    class Set {
@@ -532,4 +537,4 @@ 
## 参考资料与拓展阅读



-    [Left-Leaning Red-Black Trees](https://www.cs.princeton.edu/~rs/talks/LLRB/RedBlack.pdf) -  Robert Sedgewick Princeton University

-  [Balanced Search Trees]( https://algs4.cs.princeton.edu/lectures/33BalancedSearchTrees-2x2.pdf ) -  *Algorithms* Robert Sedgewick | Kevin Wayne
 
-    [Balanced Search Trees](https://algs4.cs.princeton.edu/lectures/33BalancedSearchTrees-2x2.pdf) -_Algorithms_Robert Sedgewick | Kevin Wayne