Commit 14b6e53

马力马力

马力

authored and

马力

committed

Add C++ implementation

Signed-off-by: 马力 <mali0921@HPCL202007007deMacBook-Pro.local>

1 parent eb736e2 commit 14b6e53Copy full SHA for 14b6e53

File tree

+74

-0

lines changed

+74

-0

lines changed

Lines changed: 34 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,34 @@`
	`1`	`+#include <bits/stdc++.h>`
	`2`	`+`
	`3`	`+using namespace std;`
	`4`	`+`
	`5`	`+/**`
	`6`	`+ * Definition for a binary tree node.`
	`7`	`+ * struct TreeNode {`
	`8`	`+ * int val;`
	`9`	`+ * TreeNode *left;`
	`10`	`+ * TreeNode *right;`
	`11`	`+ * TreeNode() : val(0), left(nullptr), right(nullptr) {}`
	`12`	`+ * TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}`
	`13`	`+ * TreeNode(int x, TreeNode left, TreeNode right) : val(x), left(left), right(right) {}`
	`14`	`+ * };`
	`15`	`+ */`
	`16`	`+class Solution {`
	`17`	`+public:`
	`18`	`+ vector<int> preorderTraversal(TreeNode* root) {`
	`19`	`+ vector<int> res;`
	`20`	`+ stack<TreeNode *> stk;`
	`21`	`+ while (!stk.empty() \|\| root != nullptr) {`
	`22`	`+ if (root != nullptr) {`
	`23`	`+ res.push_back(root->val);`
	`24`	`+ stk.push(root);`
	`25`	`+ root = root->left;`
	`26`	`+ } else {`
	`27`	`+ root = stk.top();`
	`28`	`+ stk.pop();`
	`29`	`+ root = root->right;`
	`30`	`+ }`
	`31`	`+ }`
	`32`	`+ return res;`
	`33`	`+ }`
	`34`	`+};`

Lines changed: 40 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,40 @@`
	`1`	`+#include <bits/stdc++.h>`
	`2`	`+`
	`3`	`+using namespace std;`
	`4`	`+`
	`5`	`+/**`
	`6`	`+ * Definition for a binary tree node.`
	`7`	`+ * struct TreeNode {`
	`8`	`+ * int val;`
	`9`	`+ * TreeNode *left;`
	`10`	`+ * TreeNode *right;`
	`11`	`+ * TreeNode() : val(0), left(nullptr), right(nullptr) {}`
	`12`	`+ * TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}`
	`13`	`+ * TreeNode(int x, TreeNode left, TreeNode right) : val(x), left(left), right(right) {}`
	`14`	`+ * };`
	`15`	`+ */`
	`16`	`+class Solution {`
	`17`	`+public:`
	`18`	`+ vector<int> postorderTraversal(TreeNode* root) {`
	`19`	`+ vector<int> res;`
	`20`	`+ stack<pair<TreeNode , TreeNode >> stk;`
	`21`	`+ while (!stk.empty() \|\| root != nullptr) {`
	`22`	`+ if (root != nullptr) {`
	`23`	`+ stk.push(make_pair(root, root->right));`
	`24`	`+ root = root->left;`
	`25`	`+ } else {`
	`26`	`+ if (stk.top().second != nullptr) {`
	`27`	`+ // Into right`
	`28`	`+ root = stk.top().second;`
	`29`	`+ stk.top().second = nullptr;`
	`30`	`+ } else {`
	`31`	`+ // True backtracing`
	`32`	`+ res.push_back(stk.top().first->val);`
	`33`	`+ stk.pop();`
	`34`	`+ root = nullptr;`
	`35`	`+ }`
	`36`	`+ }`
	`37`	`+ }`
	`38`	`+ return res;`
	`39`	`+ }`
	`40`	`+};`

Comments

(0)