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feat: add solutions to lc problem: No.1028 (#4099)
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‎solution/1000-1099/1028.Recover a Tree From Preorder Traversal/README.md

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Original file line numberDiff line numberDiff line change
@@ -182,6 +182,92 @@ public:
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};
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```
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#### TypeScript
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```ts
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function recoverFromPreorder(traversal: string): TreeNode | null {
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const stack: TreeNode[] = [];
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let i = 0;
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while (i < traversal.length) {
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let depth = 0;
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while (i < traversal.length && traversal[i] === '-') {
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depth++;
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i++;
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}
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let num = 0;
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while (i < traversal.length && !Number.isNaN(+traversal[i])) {
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num = num * 10 + +traversal[i];
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i++;
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}
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// Create the new node
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const newNode = new TreeNode(num);
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while (stack.length > depth) {
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stack.pop();
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}
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if (stack.length > 0) {
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const i = stack.length - 1;
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if (stack[i].left === null) {
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stack[i].left = newNode;
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} else {
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stack[i].right = newNode;
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}
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}
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stack.push(newNode);
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}
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return stack.length ? stack[0] : null;
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}
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```
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#### JavaScript
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```js
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function recoverFromPreorder(traversal) {
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const stack = [];
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let i = 0;
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while (i < traversal.length) {
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let depth = 0;
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while (i < traversal.length && traversal[i] === '-') {
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depth++;
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i++;
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}
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let num = 0;
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while (i < traversal.length && !Number.isNaN(+traversal[i])) {
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num = num * 10 + +traversal[i];
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i++;
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}
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// Create the new node
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const newNode = new TreeNode(num);
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while (stack.length > depth) {
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stack.pop();
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}
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if (stack.length > 0) {
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const i = stack.length - 1;
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if (stack[i].left === null) {
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stack[i].left = newNode;
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} else {
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stack[i].right = newNode;
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}
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}
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stack.push(newNode);
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}
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return stack.length ? stack[0] : null;
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}
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```
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<!-- tabs:end -->
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<!-- solution:end -->

‎solution/1000-1099/1028.Recover a Tree From Preorder Traversal/README_EN.md

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Original file line numberDiff line numberDiff line change
@@ -177,6 +177,92 @@ public:
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};
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```
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#### TypeScript
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```ts
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function recoverFromPreorder(traversal: string): TreeNode | null {
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const stack: TreeNode[] = [];
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let i = 0;
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while (i < traversal.length) {
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let depth = 0;
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while (i < traversal.length && traversal[i] === '-') {
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depth++;
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i++;
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}
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let num = 0;
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while (i < traversal.length && !Number.isNaN(+traversal[i])) {
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num = num * 10 + +traversal[i];
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i++;
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}
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// Create the new node
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const newNode = new TreeNode(num);
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while (stack.length > depth) {
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stack.pop();
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}
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if (stack.length > 0) {
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const i = stack.length - 1;
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if (stack[i].left === null) {
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stack[i].left = newNode;
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} else {
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stack[i].right = newNode;
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}
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}
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stack.push(newNode);
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}
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return stack.length ? stack[0] : null;
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}
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```
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#### JavaScript
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```js
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function recoverFromPreorder(traversal) {
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const stack = [];
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let i = 0;
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while (i < traversal.length) {
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let depth = 0;
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while (i < traversal.length && traversal[i] === '-') {
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depth++;
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i++;
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}
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let num = 0;
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while (i < traversal.length && !Number.isNaN(+traversal[i])) {
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num = num * 10 + +traversal[i];
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i++;
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}
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// Create the new node
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const newNode = new TreeNode(num);
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while (stack.length > depth) {
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stack.pop();
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}
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if (stack.length > 0) {
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const i = stack.length - 1;
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if (stack[i].left === null) {
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stack[i].left = newNode;
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} else {
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stack[i].right = newNode;
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}
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}
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stack.push(newNode);
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}
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return stack.length ? stack[0] : null;
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}
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```
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<!-- tabs:end -->
181267

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<!-- solution:end -->

‎solution/1000-1099/1028.Recover a Tree From Preorder Traversal/Solution.js

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Original file line numberDiff line numberDiff line change
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function recoverFromPreorder(traversal) {
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const stack = [];
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let i = 0;
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while (i < traversal.length) {
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let depth = 0;
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while (i < traversal.length && traversal[i] === '-') {
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depth++;
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i++;
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}
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let num = 0;
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while (i < traversal.length && !Number.isNaN(+traversal[i])) {
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num = num * 10 + +traversal[i];
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i++;
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}
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// Create the new node
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const newNode = new TreeNode(num);
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while (stack.length > depth) {
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stack.pop();
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}
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if (stack.length > 0) {
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const i = stack.length - 1;
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if (stack[i].left === null) {
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stack[i].left = newNode;
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} else {
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stack[i].right = newNode;
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}
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}
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stack.push(newNode);
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}
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return stack.length ? stack[0] : null;
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}

‎solution/1000-1099/1028.Recover a Tree From Preorder Traversal/Solution.ts

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,38 @@
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function recoverFromPreorder(traversal: string): TreeNode | null {
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const stack: TreeNode[] = [];
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let i = 0;
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while (i < traversal.length) {
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let depth = 0;
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while (i < traversal.length && traversal[i] === '-') {
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depth++;
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i++;
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}
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let num = 0;
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while (i < traversal.length && !Number.isNaN(+traversal[i])) {
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num = num * 10 + +traversal[i];
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i++;
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}
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// Create the new node
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const newNode = new TreeNode(num);
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while (stack.length > depth) {
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stack.pop();
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}
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if (stack.length > 0) {
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const i = stack.length - 1;
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if (stack[i].left === null) {
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stack[i].left = newNode;
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} else {
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stack[i].right = newNode;
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}
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}
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stack.push(newNode);
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}
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return stack.length ? stack[0] : null;
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}

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