Add Vertical Order Traversal of a Binary Tree solution #220
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Claude finished @pertrai1's task in 1m 33s —— View job Code Review Complete ✓SummaryThis PR successfully moves the "Vertical Order Traversal of a Binary Tree" solution into the proper directory structure and improves code quality. The solution is algorithmically correct and handles all test cases properly. Correctness ✅The solution correctly implements vertical order traversal with proper handling of:
Mental trace verification for Example 2
Complexity AnalysisTime Complexity: O(n log n) where n is the number of nodes
Space Complexity: O(n)
Pattern Recognition: DFS + Hash Map + Multi-level SortingPrimary Pattern: DFS Traversal with Coordinate TrackingThis problem uses DFS (Depth-First Search) to traverse the tree while tracking 2D coordinates (row, col). The coordinate system transforms the tree structure into a sortable format. Why This Pattern WorksDFS is ideal here because:
Key Insight 💡The critical insight is treating the tree as a 2D coordinate system where sorting rules define the output order:
The problem is essentially asking you to map tree positions to (row, col) coordinates, then perform a multi-key sort. Most solutions fail by forgetting the tertiary sort condition (nodes at same position must be sorted by value). Code Quality ReviewStrengths
Improvements Made in This PRLooking at the diff from the original solution: vertical-order-traversal-of-a-binary-tree.ts:25 - valueMap.get(col).sort(...)
+ valueMap.get(col)!.sort(...)✅ Added non-null assertion operator ( vertical-order-traversal-of-a-binary-tree.ts:1-10 + export class TreeNode {
+ val: number;
+ left: TreeNode | null;
+ right: TreeNode | null;
+ constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
+ this.val = val === undefined ? 0 : val;
+ this.left = left === undefined ? null : left;
+ this.right = right === undefined ? null : right;
+ }
+ }✅ Exported vertical-order-traversal-of-a-binary-tree.ts:12 - function verticalTraversal(...)
+ export function verticalTraversal(...)✅ Added Minor SuggestionsComment Enhancement (optional) // sort column entries: row (ascending) -> value (ascending for ties)
const sortedNodes = valueMap.get(col)!.sort((a, b) => a[0] - b[0] || a[1] - b[1]);Common Mistakes with This Pattern
Alternative ApproachesApproach 1: BFS with Level Tracking (What You Did - Optimal)
Approach 2: DFS with Tuple ArraysStore const nodes: [number, number, number][] = [];
// ... collect nodes
nodes.sort((a, b) => a[0] - b[0] || a[1] - b[1] || a[2] - b[2]);
Approach 3: BFS with QueueTrack coordinates using a queue instead of recursion:
Related Problems for PracticeTo build pattern recognition with coordinate-based tree traversal:
Learning SummaryKey Concepts Mastered
Interview TakeawayWhen you see "vertical order" or "group by column", think:
The sorting requirements are what make this problem "Hard" - many candidates miss the value-sorting tie-breaker. Verdict: Excellent solution! The code is clean, correct, and optimal. The PR successfully reorganizes the codebase and improves code quality with proper exports. ✅ |
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Important Review skippedReview was skipped as selected files did not have any reviewable changes. 💤 Files selected but had no reviewable changes (2)
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📝 WalkthroughWalkthroughProblem documentation is reorganized by moving the README to the hard problems directory structure. The root README is updated to reflect the new problem addition, increasing Hard problem count from 14 to 15. The TypeScript implementation exports TreeNode and verticalTraversal function with minor formatting adjustments. Changes
Estimated code review effort🎯 2 (Simple) | ⏱️ ~10 minutes Poem
🚥 Pre-merge checks | ✅ 2 | ❌ 1❌ Failed checks (1 warning)
✅ Passed checks (2 passed)
✏️ Tip: You can configure your own custom pre-merge checks in the settings. ✨ Finishing touches🧪 Generate unit tests (beta)
Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out. Comment |
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🤖 Gemini Code Review (Model: Here's a review of your LeetCode solution for "Vertical Order Traversal of a Binary Tree": 1. Pattern IdentificationThis solution primarily uses Tree Traversal (Depth-First Search - DFS) combined with Coordinate Geometry and Custom Sorting. It assigns 2. Complexity Verification
3. Key InsightThe key insight is to assign a unique coordinate
By storing nodes in a 4. Edge Case AnalysisThe solution handles several important edge cases correctly:
5. Learning Points
6. Code Quality
7. Alternative Approaches
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🤖 Gemini Code Review (Model: Here's a review of your LeetCode solution for "Vertical Order Traversal of a Binary Tree": 1. Pattern IdentificationThis solution primarily uses Depth-First Search (DFS) to traverse the binary tree and collect node information. It then employs a HashMap (JavaScript 2. Complexity Verification
3. Key InsightThe core insight for this problem is the combination of:
4. Edge Case AnalysisThe current solution handles the following edge cases correctly:
5. Learning Points
6. Code Quality
7. Alternative Approaches
Overall, this is a well-implemented and correct solution that demonstrates a solid understanding of tree traversals, data structures, and sorting algorithms. Good work! |
🧮 Solution AnalysisPR: Add Vertical Order Traversal of a Binary Tree solution 📊 Code Quality ResultsESLint Analysis
🔍 Complexity Analysis💡 Analysis Tips
📁 Analysis Files CreatedDetailed analysis files have been automatically generated and committed to 🎯 Next Steps
Analysis generated for PR files only |
✅ Test ResultsTests have been executed for this pull request. 📊 Coverage Summary
Check the workflow logs for detailed test output. |
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Pull request overview
Adds a LeetCode solution + documentation for “Vertical Order Traversal of a Binary Tree” and updates the repository’s top-level index accordingly.
Changes:
- Adds a formatted problem README under
leetcode/hard/...for Vertical Order Traversal. - Updates the TypeScript solution module to export
TreeNodeandverticalTraversal. - Updates root
README.mdcounts and adds the problem link under Hard → Tree Problems; removes an extra top-level README.
Reviewed changes
Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
| leetcode/hard/1029-vertical-order-traversal-of-a-binary-tree/vertical-order-traversal-of-a-binary-tree.ts | Exports TreeNode + verticalTraversal and tightens a map access with a non-null assertion. |
| leetcode/hard/1029-vertical-order-traversal-of-a-binary-tree/README.md | Adds the problem statement/examples/constraints for the solution directory. |
| README.md | Increments solved counts and adds the problem link under Hard → Tree Problems. |
| 1029-vertical-order-traversal-of-a-binary-tree/README.md | Removes a misplaced/duplicate README outside the leetcode/ structure. |
Comments suppressed due to low confidence (1)
leetcode/hard/1029-vertical-order-traversal-of-a-binary-tree/vertical-order-traversal-of-a-binary-tree.ts:39
valueMapis effectively storing 2-element tuples[row, value], but usingnumber[][]loses that intent and type safety (e.g.,a[0],a[1],n[1]). Consider typing the entries as[row: number, val: number][](or a small interface) to make the sort/mapping safer and self-documenting.
README.md
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| ### Tree Problems | ||
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| - [1029 - Vertical Order Traversal of a Binary Tree](./leetcode/hard/1029-vertical-order-traversal-of-a-binary-tree)  |
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The LeetCode problem number in this entry/directory appears incorrect. The slug vertical-order-traversal-of-a-binary-tree corresponds to LeetCode #987 (Hard), while 1029 is a different problem; this breaks the repo’s established [number]-[problem-name] naming pattern (e.g., README.md:294-296). Please rename the directory/link text to 0987-vertical-order-traversal-of-a-binary-tree and update this list entry accordingly.
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Actionable comments posted: 1
🤖 Fix all issues with AI agents
In `@README.md`:
- Line 9: Update the LeetCode entry in the README table: change the problem ID
for "Vertical Order Traversal of a Binary Tree" from 1029 to 987 and increment
the LeetCode total count from 172 to 173 so the table row "|
[LeetCode](`#leetcode`) | Data Structures & Algorithms | 172
|" reflects the corrected ID and total.
🧹 Nitpick comments (2)
leetcode/hard/1029-vertical-order-traversal-of-a-binary-tree/vertical-order-traversal-of-a-binary-tree.ts (2)
12-16: Add algorithm pattern + complexity + example comments.This solution should include a brief algorithm description, Big‑O time/space with reasoning, and a quick example for clarity and consistency.
✍️ Suggested comment block
+// Algorithm: DFS to collect (row, col, value), then sort columns and entries by row/value. +// Time: O(N log N) from sorting columns and per-column lists; Space: O(N) for map + recursion. +// Example: root=[3,9,20,null,null,15,7] → [[9],[3,15],[20],[7]] export function verticalTraversal(root: TreeNode | null): number[][] {As per coding guidelines,
leetcode/**/*.{js,ts}: Always document both time and space complexity in Big O notation, document the algorithmic pattern used in solution code comments, and include examples in comments for complex algorithms in solution files.
18-29: Add explicit return type to the helper.TypeScript guidelines call for explicit return types, including nested functions.
✅ Minimal fix
- function traverse(node: TreeNode | null, row: number, col: number) { + function traverse(node: TreeNode | null, row: number, col: number): void {As per coding guidelines,
**/*.ts: Use explicit type annotations for function parameters and return types.
| | Platform | Focus Area | Problems Solved | | ||
| | ------------------------------- | ---------------------------- | --------------- | | ||
| | [LeetCode](#leetcode) | Data Structures & Algorithms | 171 | | ||
| | [LeetCode](#leetcode) | Data Structures & Algorithms | 172 | |
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🧩 Analysis chain
🏁 Script executed:
#!/bin/bash
# Count problem directories by difficulty
for level in easy medium hard; do
count=$(find "leetcode/$level" -mindepth 1 -maxdepth 1 -type d 2>/dev/null | wc -l)
echo "$level: $count"
done
echo "total: $(find leetcode -mindepth 2 -maxdepth 2 -type d 2>/dev/null | wc -l)"Repository: pertrai1/coding-challenges
Length of output: 109
🌐 Web query:
LeetCode problem number "Vertical Order Traversal of a Binary Tree"
💡 Result:
LeetCode problem number: 987 — Vertical Order Traversal of a Binary Tree [1][3]
Correct the LeetCode problem ID and update the total count.
The problem ID for "Vertical Order Traversal of a Binary Tree" is 987, not 1029. Additionally, the LeetCode total on line 9 should be 173, not 172, to match the actual number of problems in the directory structure (81 easy + 77 medium + 15 hard).
🤖 Prompt for AI Agents
In `@README.md` at line 9, Update the LeetCode entry in the README table: change
the problem ID for "Vertical Order Traversal of a Binary Tree" from 1029 to 987
and increment the LeetCode total count from 172 to 173 so the table row "|
[LeetCode](`#leetcode`) | Data Structures & Algorithms | 172
|" reflects the corrected ID and total.
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@codex review |
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Claude finished @pertrai1's task in 1m 50s —— View job Educational Code Review ✅SummaryThis PR successfully reorganizes the "Vertical Order Traversal of a Binary Tree" solution from the incorrect directory (1029) to the correct one (0987), and the solution itself is algorithmically correct and well-implemented. Excellent work on a challenging Hard problem! 1. Correctness Analysis ✅Algorithm VerificationThe solution correctly implements vertical order traversal with proper handling of all requirements: ✅ Core Logic
✅ Critical Edge Case: Nodes at Same Position // Line 38: First sort by row (a[0] - b[0]), THEN by value (a[1] - b[1])
.sort((a, b) => a[0] - b[0] || a[1] - b[1])Mental Trace Verification (Example 2)
✅ Other Edge Cases
2. Complexity AnalysisTime Complexity: O(n log n) ✅Breaking it down:
Dominant factor: Sorting operations → O(n log n) Space Complexity: O(n) ✅
Total: O(n) + O(h) + O(n) = O(n) since h ≤ n 3. Pattern Recognition: DFS + Hash Map + Multi-Key SortingPrimary Pattern: Tree Traversal with Coordinate MappingThis problem combines:
Why This Pattern WorksDFS Choice:
Coordinate System:
Multi-Key Sort:
💡 Key InsightThe non-obvious trick: This is fundamentally a sorting problem disguised as a tree traversal problem. The "hard" part isn't the traversal—it's realizing you need to:
Most incorrect solutions either:
Your solution nails this by cleanly separating concerns: collect during DFS, sort afterward. 4. Code Quality ReviewStrengths ✅vertical-order-traversal-of-a-binary-tree.ts:13-16 // initialize a map where:
// key = column index
// value = array of [row, node.val]
const valueMap = new Map<number, number[][]>();✅ Excellent comment explaining the data structure vertical-order-traversal-of-a-binary-tree.ts:1-10 export class TreeNode {
val: number;
left: TreeNode | null;
right: TreeNode | null;
constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
this.val = val === undefined ? 0 : val;
this.left = left === undefined ? null : left;
this.right = right === undefined ? null : right;
}
}✅ Exported for testability and reusability vertical-order-traversal-of-a-binary-tree.ts:25 valueMap.get(col)!.push([row, node.val]);✅ Correct use of non-null assertion — we just checked vertical-order-traversal-of-a-binary-tree.ts:38 const sortedNodes = valueMap.get(col)!.sort((a, b) => a[0] - b[0] || a[1] - b[1]);✅ Clean chained sort comparator for multi-level sorting Minor Suggestions1. Add Algorithm Overview Comment Consider adding a brief complexity comment at the function start: // Algorithm: DFS with coordinate tracking + multi-key sorting
// Time: O(n log n) - dominated by sorting operations
// Space: O(n) - Map storage + recursion stack
export function verticalTraversal(root: TreeNode | null): number[][] {2. Clarify Tertiary Sort in Comment Line 37's comment could be more explicit: // sort column entries: row (ascending) -> value (ascending for ties at same position)3. TypeScript Type Safety (Optional Enhancement) Your tuple type type NodeEntry = [row: number, value: number];
const valueMap = new Map<number, NodeEntry[]>();This makes 5. Common Mistakes with This Pattern🚨 Pitfalls to Avoid:
6. Alternative ApproachesApproach 1: Your DFS + Map (Optimal) ✅// Current implementation
Approach 2: BFS with Queuefunction verticalTraversal(root: TreeNode | null): number[][] {
if (!root) return [];
const queue: [TreeNode, number, number][] = [[root, 0, 0]];
const map = new Map<number, [number, number][]>();
while (queue.length) {
const [node, row, col] = queue.shift()!;
if (!map.has(col)) map.set(col, []);
map.get(col)!.push([row, node.val]);
if (node.left) queue.push([node.left, row + 1, col - 1]);
if (node.right) queue.push([node.right, row + 1, col + 1]);
}
// ... same sorting logic
}
Approach 3: Single Array + One Sortfunction verticalTraversal(root: TreeNode | null): number[][] {
const nodes: [number, number, number][] = []; // [col, row, val]
function dfs(node: TreeNode | null, row: number, col: number) {
if (!node) return;
nodes.push([col, row, node.val]);
dfs(node.left, row + 1, col - 1);
dfs(node.right, row + 1, col + 1);
}
dfs(root, 0, 0);
nodes.sort((a, b) => a[0] - b[0] || a[1] - b[1] || a[2] - b[2]);
// Group by column
const result: number[][] = [];
let prevCol = nodes[0]?.[0];
let currentGroup: number[] = [];
for (const [col, _, val] of nodes) {
if (col !== prevCol) {
result.push(currentGroup);
currentGroup = [];
prevCol = col;
}
currentGroup.push(val);
}
if (currentGroup.length) result.push(currentGroup);
return result;
}
Verdict: Your Map-based approach (Approach 1) is the cleanest and most maintainable. 7. Related Problems for PracticeTo build pattern recognition with coordinate-based tree traversals: Same Pattern, Slight Variations:
Extension Problems:
8. Learning SummaryKey Concepts Mastered ✅
Interview Takeaway 🎯When you see "vertical order" or "column-based grouping" in a tree problem:
What makes this problem "Hard":
Many candidates get 90% through this problem and fail on test cases like Example 2 where nodes 5 and 6 share position (2,0). Your solution handles this perfectly! Final Verdict ✅Excellent solution! The code is:
The PR also successfully reorganizes the codebase (1029 → 0987) and improves code quality with proper exports. Strong work on a challenging Hard problem! 🎉 |
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🤖 Gemini Code Review (Model: Here's a detailed review of the provided LeetCode solution for "Vertical Order Traversal of a Binary Tree." 1. Pattern IdentificationThis solution primarily uses Tree Traversal (Depth-First Search - DFS) combined with Hash Map (Dictionary) for grouping and Custom Sorting. The core idea is to traverse the tree, assign coordinates (column and row) to each node, store these nodes grouped by their column index, and then sort them based on the problem's specific rules. 2. Complexity Verification
3. Key InsightThe key insight for this problem is the ability to assign a unique coordinate (column, row) to every node in the binary tree and then use these coordinates to guide the output order.
This multi-level sorting requirement means you can't just do a simple traversal and print. You need to collect all nodes with their coordinates and then apply a custom sort function. The use of a 4. Edge Case AnalysisThe current solution appears robust and correctly handles the specified edge cases:
Constraints Handling:
5. Learning Points
6. Code QualityThe code quality is generally good:
// Optional improvement: minCol and maxCol are not strictly needed.
// The range of columns is implicitly handled by iterating over valueMap.keys() after traversal.
// function verticalTraversal(root: TreeNode | null): number[][] {
// const valueMap = new Map<number, Array<[number, number]>>(); // key = column index, value = array of [row, node.val]
// const traverse = (node: TreeNode | null, row: number, col: number) => {
// if (!node) {
// return;
// }
// if (!valueMap.has(col)) {
// valueMap.set(col, []);
// }
// valueMap.get(col)!.push([row, node.val]);
// traverse(node.left, row + 1, col - 1);
// traverse(node.right, row + 1, col + 1);
// };
// traverse(root, 0, 0);
// const sortedCols = Array.from(valueMap.keys()).sort((a, b) => a - b);
// return sortedCols.map((col) => {
// const sortedNodes = valueMap.get(col)!.sort((a, b) => a[0] - b[0] || a[1] - b[1]);
// return sortedNodes.map((n) => n[1]);
// });
// }7. Alternative Approaches
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Claude finished @pertrai1's task in 1m 50s —— View job Educational Code Review ✅SummaryThis PR successfully reorganizes the "Vertical Order Traversal of a Binary Tree" solution into the correct directory structure (problem #0987), and the implementation is algorithmically correct and well-crafted. Excellent work on this challenging Hard problem! 1. Correctness Analysis ✅Algorithm VerificationThe solution correctly implements all requirements: ✅ Coordinate System
✅ Grouping & Sorting
✅ Critical Edge Case: Same Position Nodes The trickiest requirement is handling nodes at identical .sort((a, b) => a[0] - b[0] || a[1] - b[1])
// ^^^^^^^^^^^^^^^^ ^^^^^^^^
// Sort by row first Then by valueMental Trace (Example 2) For Expected output: Trace:
✅ Other Edge Cases
2. Complexity AnalysisTime Complexity: O(n log n) ✅Breakdown:
Dominant Operation: Sorting → O(n log n) Space Complexity: O(n) ✅
Total: O(n) + O(h) + O(n) = O(n) (since h ≤ n) 3. Pattern RecognitionPrimary Pattern: DFS + Hash Map + Multi-Key SortingThis problem combines three fundamental techniques:
Why This Pattern WorksDFS Choice:
Hash Map Grouping:
Multi-Key Sort:
💡 Key InsightThe non-obvious realization: This is fundamentally a sorting problem disguised as a tree problem. The "Hard" difficulty comes from:
Many incorrect solutions:
Your solution excels by cleanly separating concerns: collect during DFS, sort afterward. 4. Code Quality ReviewStrengths ✅1. Clear Data Structure Documentation (vertical-order-traversal-of-a-binary-tree.ts:13-16) // initialize a map where:
// key = column index
// value = array of [row, node.val]✅ Excellent comment explaining the Map structure 2. Exported API (vertical-order-traversal-of-a-binary-tree.ts:1-10) export class TreeNode { ... }✅ Makes TreeNode testable and reusable 3. Clean Sort Chaining (vertical-order-traversal-of-a-binary-tree.ts:38) .sort((a, b) => a[0] - b[0] || a[1] - b[1])✅ Concise multi-level comparator 4. Safe Non-Null Assertions (vertical-order-traversal-of-a-binary-tree.ts:25, 38) valueMap.get(col)!.push([row, node.val]);✅ Correct use of Suggestions for Enhancement1. Add Complexity Documentation Consider adding algorithm overview at function start: // Algorithm: DFS with coordinate tracking + multi-key sorting
// Time: O(n log n) - dominated by sorting operations
// Space: O(n) - Map storage + recursion stack
export function verticalTraversal(root: TreeNode | null): number[][] {2. Enhance Sort Comment Line 37's comment could be more explicit about the tie-breaking: // sort column entries: row (ascending) → value (ascending for same position)
const sortedNodes = valueMap.get(col)!.sort((a, b) => a[0] - b[0] || a[1] - b[1]);3. TypeScript Type Safety (Optional) For even better type safety, consider named tuple types: type NodeEntry = [row: number, value: number];
const valueMap = new Map<number, NodeEntry[]>();This makes 5. Common Mistakes with This Pattern🚨 Pitfalls to Avoid:
6. Alternative ApproachesApproach 1: Your DFS + Map (Optimal) ✅Current Implementation
Approach 2: BFS with Queuefunction verticalTraversal(root: TreeNode | null): number[][] {
if (!root) return [];
const queue: [TreeNode, number, number][] = [[root, 0, 0]];
const map = new Map<number, [number, number][]>();
while (queue.length) {
const [node, row, col] = queue.shift()!;
if (!map.has(col)) map.set(col, []);
map.get(col)!.push([row, node.val]);
if (node.left) queue.push([node.left, row + 1, col - 1]);
if (node.right) queue.push([node.right, row + 1, col + 1]);
}
// ... same sorting logic
}
Approach 3: Single Array + Global Sortfunction verticalTraversal(root: TreeNode | null): number[][] {
const nodes: [number, number, number][] = []; // [col, row, val]
function dfs(node: TreeNode | null, row: number, col: number) {
if (!node) return;
nodes.push([col, row, node.val]);
dfs(node.left, row + 1, col - 1);
dfs(node.right, row + 1, col + 1);
}
dfs(root, 0, 0);
nodes.sort((a, b) => a[0] - b[0] || a[1] - b[1] || a[2] - b[2]);
// Group by column into final result
const result: number[][] = [];
let prevCol = nodes[0]?.[0];
let currentGroup: number[] = [];
for (const [col, _, val] of nodes) {
if (col !== prevCol) {
result.push(currentGroup);
currentGroup = [];
prevCol = col;
}
currentGroup.push(val);
}
if (currentGroup.length) result.push(currentGroup);
return result;
}
Verdict: Your Map-based approach (Approach 1) is the cleanest and most maintainable. 7. Related Problems for PracticeSame Pattern, Easier Variations:1. LeetCode 314 - Binary Tree Vertical Order Traversal (Medium)
2. LeetCode 102 - Binary Tree Level Order Traversal (Medium)
3. LeetCode 199 - Binary Tree Right Side View (Medium)
Extension Problems:4. LeetCode 545 - Boundary of Binary Tree (Medium)
5. LeetCode 1110 - Delete Nodes And Return Forest (Medium)
8. Learning SummaryKey Concepts Mastered ✅
Interview Takeaway 🎯When you see "vertical order" or "column grouping" in tree problems:
What makes this problem "Hard":
Many candidates get 90% through and fail on Example 2 where nodes 5 and 6 share position Final Verdict ✅Outstanding solution! The code is:
The PR also successfully reorganizes the codebase and improves code quality with proper exports. Strong work on this challenging Hard problem! 🎉 |
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🤖 Gemini Code Review (Model: Here's a review of your LeetCode solution for "Vertical Order Traversal of a Binary Tree." 1. Pattern IdentificationThis solution primarily uses Tree Traversal, specifically a Depth-First Search (DFS), combined with Hashing/Mapping to store and group nodes by their column index. Finally, Sorting is applied to arrange the results according to the problem's specific ordering rules. 2. Complexity Verification
3. Key InsightThe key insight for this problem is the assignment of a unique coordinate
The solution correctly captures these insights by using a map to group by column, then sorting the column keys, and finally sorting the lists within each column using a custom comparator 4. Edge Case AnalysisThe current solution handles common edge cases correctly:
5. Learning Points
6. Code Quality
7. Alternative Approaches
The chosen DFS approach is perfectly valid and efficient for this problem in JavaScript, correctly addressing all requirements. |
📅 Spaced Repetition Reviews Scheduled!Great job solving #0987 - Vertical Order Traversal Of A Binary Tree! 🎉 To help you retain this knowledge long-term, I've scheduled 5 review sessions using spaced repetition:
What to expect:
🧠 Why Spaced Repetition?Research shows that reviewing material at increasing intervals dramatically improves retention. This adaptive scheduling ensures optimal spacing based on when you actually complete each review! Check |
…A Binary Tree Problem: #0987 - Vertical Order Traversal Of A Binary Tree PR: #220 First review scheduled (subsequent reviews auto-scheduled on completion) [skip ci]
Summary by CodeRabbit
New Features
Documentation
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