rbt

#include <stdio.h>#include <stdlib.h>#define BLACK 0#define RED   1typedef struct rbnode {int color;int key;struct rbnode *parent;struct rbnode *left;struct rbnode *right;} RBNode;typedef RBNode *RBTree;// 整一个空子节点，作为哨兵RBNode Nil = {BLACK, 0, NULL, NULL, NULL};RBNode *nil = &Nil;RBNode *FindMin(RBTree rbt){while (rbt != nil && rbt->left != nil) {rbt = rbt->left;}return rbt;}RBNode *FindPos(RBTree rbt, int key){// if (rbt == nil)// return nil;// // if (key < rbt->key)// return FindPos(rbt->left, key);// else if (key > rbt->key)// return FindPos(rbt->right, key);// else// return rbt;while (rbt != nil && key != rbt->key) {if (key < rbt->key)rbt = rbt->left;else/* if (e > t->e) */rbt = rbt->right;}return rbt;}// 使x成为左孩子// y = x->right// x->right = y->left// y->left = xRBTree LeftRotate(RBTree rbt, RBNode *x){RBNode *y = x->right; // set yx->right = y->left; // turn y's left subtree into x's right subtreeif (y->left != nil)y->left->parent = x;y->parent = x->parent; // link x's parent to yif (x->parent == nil) // x为根（root）rbt = y;else if (x == x->parent->left) // 确定x为父亲的左孩子还是右孩子x->parent->left = y;elsex->parent->right = y;y->left = x; // put x on y's left   x->parent = y;return rbt;}// 使y成为右孩子// x = y->left// y->left = x->right// x->right = yRBTree RightRotate(RBTree rbt, RBNode *y){RBNode *x = y->left;y->left = x->right;if (x->right != nil)x->right->parent = y;x->parent = y->parent;if (y->parent == nil)rbt = x;else if (y == y->parent->left)y->parent->left = x;elsey->parent->right = x;x->right = y;y->parent = x;return rbt;}RBTree RBInsertFixup(RBTree rbt, RBNode *z, RBNode *y){/*RBNode *y = nil; // */while (z->parent->color == RED) {if (z->parent == z->parent->parent->left) {y = z->parent->parent->right;if (y->color == RED) {             // case 1z->parent->color = BLACK;y->color = BLACK;z->parent->parent->color = RED;z = z->parent->parent; // 更新z的位置} else {if (z == z->parent->right) { // 右孩子z = z->parent; // 更新z的位置if (z->right != nil)rbt = LeftRotate(rbt, z);}z->parent->color = BLACK;z->parent->parent->color = RED;if (z->parent->parent->left != nil)rbt = RightRotate(rbt, z->parent->parent);}} else {y = z->parent->parent->left;if (y->color == RED) {z->parent->color = BLACK;y->color = BLACK;z->parent->parent->color = RED;z = z->parent->parent;} else {if (z == z->parent->left){z = z->parent;if (z->right != nil)rbt = LeftRotate(rbt, z);}z->parent->color = BLACK;z->parent->parent->color = RED;if (z->parent->parent->left != nil)rbt = RightRotate(rbt, z->parent->parent);}}}rbt->color = BLACK;return rbt;}RBTree RBInsert(RBTree rbt, RBNode *z){RBNode *y = nil;RBNode *x = rbt;while (x != nil) { // 找到插入点y = x; // 记录父节点if (z->key < x->key)x = x->left;else x = x->right;}z->parent = y; // 确定z的父节点，进行插入if (y == nil) // z为新的根节点rbt = z;else if (z->key < y->key) // 确定z为y的左孩子还是有孩子y->left = z;else /*if (z->key >= y->key)*/y->right = z;z->left = nil;z->right = nil;z->color = RED;rbt = RBInsertFixup(rbt, z, y);return rbt;}RBTree RBTransplant(RBTree rbt, RBNode *u, RBNode *v){if (u->parent == nil)rbt = v;else if (u == u->parent->left) // 左孩子u->parent->left = v;elseu->parent->right = v; // 右孩子v->parent = u->parent;return rbt;}RBTree RBDelectFixup(RBTree rbt, RBNode *x){RBNode *w;while (x != rbt && x->color == BLACK) {if (x == x->parent->left) { // 左孩子w = x->parent->right; // x的兄弟if (w->color == RED) { // case 1w->color = BLACK;x->parent->color = RED;if (x->parent->right != nil)rbt = LeftRotate(rbt, x->parent);w = x->parent->right;}if (w->left->color == BLACK && w->right->color == BLACK) { // case 2w->color = RED;x = x->parent;} else { if (w->right->color == BLACK) { // case 3w->left->color = BLACK;w->color = RED;if (w->left != nil)rbt = RightRotate(rbt, w);}w->color = x->parent->color;  x->parent->color = BLACK;w->right->color = BLACK;if (x->parent->right != nil)rbt = LeftRotate(rbt, x->parent);x = rbt;}} else { // x == x->parent->left  // 修改包括旋转的方向w = x->parent->left; // x的兄弟if (w->color == RED) { // case 1w->color = BLACK;x->parent->color = RED;if (x->parent->left != nil)rbt = RightRotate(rbt, x->parent);w = x->parent->left;}if (w->left->color == BLACK && w->right->color == BLACK) { // case 2w->color = RED;x = x->parent;} else { if (w->left->color == BLACK) { // case 3w->right->color = BLACK;w->color = RED;if (w->right != nil)rbt = LeftRotate(rbt, w);}w->color = x->parent->color; // case 4x->parent->color = BLACK;w->left->color = BLACK;if (x->parent->left != nil)rbt = RightRotate(rbt, x->parent);x = rbt;}}}x->color = BLACK;return rbt;}RBTree RBDelect(RBTree rbt, RBNode *z){RBNode *x;RBNode *y = z;int yoclr = y->color; // y-original-colorif (z->left == nil) { // 没有左孩子x = z->right;rbt = RBTransplant(rbt, z, z->right);} else if (z->right == nil) { // 没有右孩子x = z->left;rbt = RBTransplant(rbt, z, z->left);} else { // 有两个孩子y = FindMin(z->right);yoclr = y->color;x = y->right;if (y->parent == z) {x->parent = y;} else {RBTransplant(rbt, y, y->right);y->right = z->right;y->right->parent = y;}rbt = RBTransplant(rbt, z, y);y->left = z->left;y->left->parent = y;y->color = z->color;free(z);}if (yoclr == BLACK)rbt = RBDelectFixup(rbt, x);return rbt;}void PreorderPrint(RBTree rbt){if (rbt != nil) {printf("%d\t", rbt->key);PreorderPrint(rbt->left);PreorderPrint(rbt->right);}}void InorderPrint(RBTree rbt){if (rbt != nil) {InorderPrint(rbt->left);printf("%d\t", rbt->key);InorderPrint(rbt->right);}}void PostorderPrint(RBTree rbt){if (rbt != nil) {PostorderPrint(rbt->left);PostorderPrint(rbt->right);printf("%d\t", rbt->key);}}int main(){int arr[] = {19, 13, 23, 8, 17, 21, 43, 3, 11, 14};int len = sizeof(arr) / sizeof(arr[0]);RBTree rbt = nil;for (int i = 0; i < len; i++) {RBNode *x = (RBNode *)malloc(sizeof(RBNode));if (!x) {printf("x malloc error\n");return -1;}x->key = arr[i];x->parent = x->left = x->right = nil;rbt = RBInsert(rbt, x);}printf("preorder:\n");PreorderPrint(rbt);printf("\n");printf("inorder:\n");InorderPrint(rbt);printf("\n");printf("postorder:\n");PostorderPrint(rbt);printf("\n");for (int i = 0; i < len; i++) {rbt = RBDelect(rbt, FindPos(rbt, arr[i]));printf("inorder:\n");InorderPrint(rbt);printf("\n");}system("pause");return 0;}