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本帖最后由 糖逗 于 2020-5-8 17:47 编辑
题目描述:
- 给定一个二叉树,原地将它展开为链表。
- 例如,给定二叉树
- 1
- / \
- 2 5
- / \ \
- 3 4 6
- 将其展开为:
- 1
- \
- 2
- \
- 3
- \
- 4
- \
- 5
- \
- 6
- 来源:力扣(LeetCode)
- 链接:https://leetcode-cn.com/problems/flatten-binary-tree-to-linked-list
- 著作权归领扣网络所有。商业转载请联系官方授权,非商业转载请注明出处。
复制代码
核心代码:
- #include<iostream>
- #include <malloc.h>
- #include <vector>
- #include <math.h>
- #include <queue>
- #include<algorithm>
- using namespace std;
- struct TreeNode{
- int val;
- TreeNode* left;
- TreeNode* right;
- TreeNode(int x): val(x), left(NULL), right(NULL){
- }
- };
- TreeNode* CreateTree(vector<int> input){
- TreeNode* res = (TreeNode*)malloc(sizeof(TreeNode)*input.size());
- for(int i = 0; i < input.size(); i++){
- res[i].val = input[i];
- res[i].left = NULL;
- res[i].right = NULL;
- }
- for(int i= 0; i < input.size(); i++){
- if(2*i+1 < input.size()){
- res[i].left = &res[2*i+1];
- }
- if(2*i+2 < input.size()){
- res[i].right = &res[2*i+2];
- }
-
- }
- return res;
-
- }
- void middle(TreeNode* root, vector<vector<int> >& res, int left, int right, int depth){
- if(root == NULL) return;
- int insert = left + (right - left) / 2;
- res[depth][insert] = root->val;
-
- middle(root->left, res, left, insert - 1, depth + 1);
- middle(root->right, res, insert + 1, right, depth + 1);
- }
- int treeDepth(TreeNode* root){
- if(root == NULL || root -> val == 0) return 0;
- return max(treeDepth(root->left) + 1, treeDepth(root->right) + 1);
- }
-
- void PrintTree(TreeNode* root) {
- int depth = treeDepth(root);
- int width = pow(2, depth) - 1;
- vector<vector<int> > res(depth, vector<int>(width, 0));
- middle(root, res, 0, width - 1, 0);
- for(int i = 0; i < res.size(); i++){
- for(int j = 0; j < res[i].size();j++){
- if(res[i][j] == 0){
- cout << " ";
- }
- else{
- cout << res[i][j];
- }
-
- }
- cout << endl;
- }
- cout << "------------------" << endl;
- }
- void flatten(TreeNode* root){
- if(root == NULL) return;
- if(root -> left != NULL){
- TreeNode* temp = root -> left;
- while(temp -> right != NULL){
- temp = temp -> right;
- }
- temp -> right = root -> right;
- root -> right = root -> left;
- root -> left = NULL;
- }
- flatten(root -> right);
- }
- void print_right_tree(TreeNode* root){
- int i = 0;
- while(root -> right != NULL){
- if(root -> val != 0){
- cout << root -> val << endl;
- }
- root = root -> right;
- }
- cout << root -> val << endl;
- return;
- }
- int main(void){
- cout << "please send the number for the tree" << endl;
- vector<int> input;
- int number;
- while(cin >> number){
- input.push_back(number);
- }
- TreeNode* root = CreateTree(input);
- PrintTree(root);
- flatten(root);
- print_right_tree(root);
-
- return 0;
- }
复制代码
注意事项:
1.参考链接:https://leetcode-cn.com/problems ... dan-by-xiao-zhu-bu/ |
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