红黑树(RedBlackTree)
#define BLACK 1 #define RED 0 #include <iostream> using namespace std; class bst { private: struct Node { int value; bool color; Node *leftTree, *rightTree, *parent; Node() : value(0), color(RED), leftTree(NULL), rightTree(NULL), parent(NULL) { } Node* grandparent() { if(parent == NULL){ return NULL; } return parent->parent; } Node* uncle() { if(grandparent() == NULL) { return NULL; } if(parent == grandparent()->rightTree) return grandparent()->leftTree; else return grandparent()->rightTree; } Node* sibling() { if(parent->leftTree == this) return parent->rightTree; else return parent->leftTree; } }; void rotate_right(Node *p){ Node *gp = p->grandparent(); Node *fa = p->parent; Node *y = p->rightTree; fa->leftTree = y; if(y != NIL) y->parent = fa; p->rightTree = fa; fa->parent = p; if(root == fa) root = p; p->parent = gp; if(gp != NULL){ if(gp->leftTree == fa) gp->leftTree = p; else gp->rightTree = p; } } void rotate_left(Node *p){ if(p->parent == NULL){ root = p; return; } Node *gp = p->grandparent(); Node *fa = p->parent; Node *y = p->leftTree; fa->rightTree = y; if(y != NIL) y->parent = fa; p->leftTree = fa; fa->parent = p; if(root == fa) root = p; p->parent = gp; if(gp != NULL){ if(gp->leftTree == fa) gp->leftTree = p; else gp->rightTree = p; } } void inorder(Node *p){ if(p == NIL) return; if(p->leftTree) inorder(p->leftTree); cout << p->value << " "; if(p->rightTree) inorder(p->rightTree); } string outputColor (bool color) { return color ? "BLACK" : "RED"; } Node* getSmallestChild(Node *p){ if(p->leftTree == NIL) return p; return getSmallestChild(p->leftTree); } bool delete_child(Node *p, int data){ if(p->value > data){ if(p->leftTree == NIL){ return false; } return delete_child(p->leftTree, data); } else if(p->value < data){ if(p->rightTree == NIL){ return false; } return delete_child(p->rightTree, data); } else if(p->value == data){ if(p->rightTree == NIL){ delete_one_child (p); return true; } Node *smallest = getSmallestChild(p->rightTree); swap(p->value, smallest->value); delete_one_child (smallest); return true; }else{ return false; } } void delete_one_child(Node *p){ Node *child = p->leftTree == NIL ? p->rightTree : p->leftTree; if(p->parent == NULL && p->leftTree == NIL && p->rightTree == NIL){ p = NULL; root = p; return; } if(p->parent == NULL){ delete p; child->parent = NULL; root = child; root->color = BLACK; return; } if(p->parent->leftTree == p){ p->parent->leftTree = child; } else { p->parent->rightTree = child; } child->parent = p->parent; if(p->color == BLACK){ if(child->color == RED){ child->color = BLACK; } else delete_case (child); } delete p; } void delete_case(Node *p){ if(p->parent == NULL){ p->color = BLACK; return; } if(p->sibling()->color == RED) { p->parent->color = RED; p->sibling()->color = BLACK; if(p == p->parent->leftTree) rotate_left(p->sibling()); else rotate_right(p->sibling()); } if(p->parent->color == BLACK && p->sibling()->color == BLACK && p->sibling()->leftTree->color == BLACK && p->sibling()->rightTree->color == BLACK) { p->sibling()->color = RED; delete_case(p->parent); } else if(p->parent->color == RED && p->sibling()->color == BLACK && p->sibling()->leftTree->color == BLACK && p->sibling()->rightTree->color == BLACK) { p->sibling()->color = RED; p->parent->color = BLACK; } else { if(p->sibling()->color == BLACK) { if(p == p->parent->leftTree && p->sibling()->leftTree->color == RED && p->sibling()->rightTree->color == BLACK) { p->sibling()->color = RED; p->sibling()->leftTree->color = BLACK; rotate_right(p->sibling()->leftTree); } else if(p == p->parent->rightTree && p->sibling()->leftTree->color == BLACK && p->sibling()->rightTree->color == RED) { p->sibling()->color = RED; p->sibling()->rightTree->color = BLACK; rotate_left(p->sibling()->rightTree); } } p->sibling()->color = p->parent->color; p->parent->color = BLACK; if(p == p->parent->leftTree){ p->sibling()->rightTree->color = BLACK; rotate_left(p->sibling()); } else { p->sibling()->leftTree->color = BLACK; rotate_right(p->sibling()); } } } void insert(Node *p, int data){ if(p->value >= data){ if(p->leftTree != NIL) insert(p->leftTree, data); else { Node *tmp = new Node(); tmp->value = data; tmp->leftTree = tmp->rightTree = NIL; tmp->parent = p; p->leftTree = tmp; insert_case (tmp); } } else { if(p->rightTree != NIL) insert(p->rightTree, data); else { Node *tmp = new Node(); tmp->value = data; tmp->leftTree = tmp->rightTree = NIL; tmp->parent = p; p->rightTree = tmp; insert_case (tmp); } } } void insert_case(Node *p){ if(p->parent == NULL){ root = p; p->color = BLACK; return; } if(p->parent->color == RED){ if(p->uncle()->color == RED) { p->parent->color = p->uncle()->color = BLACK; p->grandparent()->color = RED; insert_case(p->grandparent()); } else { if(p->parent->rightTree == p && p->grandparent()->leftTree == p->parent) { rotate_left (p); rotate_right (p); p->color = BLACK; p->leftTree->color = p->rightTree->color = RED; } else if(p->parent->leftTree == p && p->grandparent()->rightTree == p->parent) { rotate_right (p); rotate_left (p); p->color = BLACK; p->leftTree->color = p->rightTree->color = RED; } else if(p->parent->leftTree == p && p->grandparent()->leftTree == p->parent) { p->parent->color = BLACK; p->grandparent()->color = RED; rotate_right(p->parent); } else if(p->parent->rightTree == p && p->grandparent()->rightTree == p->parent) { p->parent->color = BLACK; p->grandparent()->color = RED; rotate_left(p->parent); } } } } void DeleteTree(Node *p){ if(!p || p == NIL){ return; } DeleteTree(p->leftTree); DeleteTree(p->rightTree); delete p; } public: bst() { NIL = new Node(); NIL->color = BLACK; root = NULL; } ~bst() { if (root) DeleteTree (root); delete NIL; } void inorder() { if(root == NULL) return; inorder (root); cout << endl; } void insert (int x) { if(root == NULL){ root = new Node(); root->color = BLACK; root->leftTree = root->rightTree = NIL; root->value = x; } else { insert(root, x); } } bool delete_value (int data) { return delete_child(root, data); } private: Node *root, *NIL; };