C二叉搜索树代码
目录
C++二叉搜索树代码
代码一，对应力扣二叉搜索树中的检索，代码见下
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
TreeNode* searchBST(TreeNode* root, int val) {
if(root == NULL){
return NULL;
}
if(root->val < val){
return searchBST(root->right, val);
}else if(root->val > val){
return searchBST(root->left, val);
}else{
return root;
}
}
};代码二，对应力扣 二叉搜索树的范围和，代码见下
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
int rangeSumBST(TreeNode* root, int low, int high) {
if(root == NULL){
return 0;
}
int sum = 0;
if(root->val >= low && root->val <= high){
sum += root->val;
}
sum += rangeSumBST(root->left, low, high);
sum += rangeSumBST(root->right, low, high);
return sum;
}
};代码三，将有序数组转化为二叉搜索树，代码见下：
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
TreeNode* sortArray(vector<int>& nums, int l, int r){
if(l > r){
return NULL;
}
int mid = (l + r)/2;
TreeNode* node = new TreeNode(nums[mid]);
node->left = sortArray(nums, l, mid-1);
node->right = sortArray(nums, mid+1, r);
return node;
}
public:
TreeNode* sortedArrayToBST(vector<int>& nums) {
return sortArray(nums, 0, nums.size()-1);
}
};代码四，对应力扣 验证二叉搜索树，代码见下
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
vector<int> ret;
void inOrder(TreeNode* root){
if(root){
inOrder(root->left);
ret.push_back(root->val);
inOrder(root->right);
}
}
public:
bool isValidBST(TreeNode* root) {
ret.clear();
inOrder(root);
for(int i=1; i<ret.size(); ++i){
if(ret[i] < ret[i-1]){
return false;
}
}
return true;
}
};