AVL添加(c语言)
作者:互联网
平衡二叉树,是一种二叉排序树,其中每个结点的左子树和右子树的高度差至多等于1。它是一种高度平衡的二叉排序树。现二叉平衡树结点定义如下:
typedef struct node
{
int val;
struct node *left;
struct node *right;
struct node *parent;
int height;
} node_t;
请实现平衡二叉树的插入算法:
//向根为 root 的平衡二叉树插入新元素 val,成功后返回新平衡二叉树根结点
node_t *avl_insert(node_t *root, int val);
答案:
注意:对于这个parent弄得不是很清楚,希望有大佬可以指点一下。其实没有parent也能过。。。
node_t* Insert(node_t* T, int X);
int GetHeight(node_t* T);
int Max(int a, int b);
node_t* SingleLeftRotation(node_t* A);
node_t* DoubleLeftRightRotation(node_t* A);
node_t* SingleRightRotation(node_t* A);
node_t* DoubleRightLeftRotation(node_t* A);
int Max(int a, int b)
{
return a > b ? a : b;
}
int GetHeight(node_t* T)
{
if (T)
return T->height;
else
return 0;
}
node_t* SingleLeftRotation(node_t* A) //左单旋
{
node_t* B;
B = A->left;
A->left = B->right;
B->right = A;
A->height = Max(GetHeight(A->left), GetHeight(A->right)) + 1;
B->height = Max(GetHeight(B->left), GetHeight(B->right)) + 1;
return B;
}
node_t* DoubleLeftRightRotation(node_t* A) //左右双旋
{
A->left = SingleRightRotation(A->left);
return SingleLeftRotation(A);
}
node_t* SingleRightRotation(node_t* A) //右单旋
{
node_t* B;
B = A->right;
A->right = B->left;
B->left = A;
A->height = Max(GetHeight(A->left), GetHeight(A->right)) + 1;
B->height = Max(GetHeight(B->left), GetHeight(B->right)) + 1;
return B;
}
node_t* DoubleRightLeftRotation(node_t* A) //右左双旋
{
A->right = SingleLeftRotation(A->right);
return SingleRightRotation(A);
}
node_t* avl_insert(node_t* root, int val)
{
node_t* parentNode = NULL;
if (!root) {
root = (node_t*)malloc(sizeof(node_t));
root->left = root->right = root->parent = NULL;
root->val = val;
root->height = 1;
} else if (val < root->val) {
parentNode = root->left;
root->left = avl_insert(root->left, val);
if (GetHeight(root->left) - GetHeight(root->right) == 2) {
if (val < root->left->val)
root = SingleLeftRotation(root);
else {
root = DoubleLeftRightRotation(root);
}
}
} else if (val > root->val) {
parentNode = root->left;
root->right = avl_insert(root->right, val);
if (GetHeight(root->right) - GetHeight(root->left) == 2) {
if (val > root->right->val)
root = SingleRightRotation(root);
else
root = DoubleRightLeftRotation(root);
}
}
root->parent = parentNode;
root->height = Max(GetHeight(root->left), GetHeight(root->right)) + 1;
return root;
}
标签:node,right,语言,val,GetHeight,AVL,添加,root,left 来源: https://blog.csdn.net/weixin_45454859/article/details/106824446