Challenges for New Users

LeetCode is the golden standard for technical interviews . LeetCode problems are widely used during technical interviews at companies like Facebook, Hulu and Google. In the face of tight and limited job preparation time, this set of selected high-frequency interview problems can help you improve efficiently and greatly increase the possibility of obtaining an offer.

LeetCode Curated Algo 170

Aiming for Microsoft? This problems list will give you a preliminary grasp of their interview style and test sites, and conduct simulation exercises in advance. The list is updated based on how frequently problems appear in an interview.

LeetCode Curated SQL 70

Read N Characters Given Read4

read-n-characters-given-read4

String

Simulation

Interactive

Read N Characters Given read4 II - Call Multiple Times

read-n-characters-given-read4-ii-call-multiple-times

Longest Substring with At Most Two Distinct Characters

longest-substring-with-at-most-two-distinct-characters

Hash Table

Sliding Window

One Edit Distance

one-edit-distance

Two Pointers

Missing Ranges

missing-ranges

Array

Two Sum III - Data structure design

two-sum-iii-data-structure-design

Design

Data Stream

Reverse Words in a String II

reverse-words-in-a-string-ii

Shortest Word Distance

shortest-word-distance

Shortest Word Distance II

shortest-word-distance-ii

Shortest Word Distance III

shortest-word-distance-iii

Strobogrammatic Number II

strobogrammatic-number-ii

Recursion

Group Shifted Strings

group-shifted-strings

Count Univalue Subtrees

count-univalue-subtrees

Tree

Depth-First Search

Binary Tree

Flatten 2D Vector

flatten-2d-vector

Iterator

Meeting Rooms

meeting-rooms

Sorting

Meeting Rooms II

meeting-rooms-ii

Greedy

Heap (Priority Queue)

Prefix Sum

Factor Combinations

factor-combinations

Backtracking

Verify Preorder Sequence in Binary Search Tree

verify-preorder-sequence-in-binary-search-tree

Stack

Binary Search Tree

Monotonic Stack

Paint House

paint-house

Dynamic Programming

3Sum Smaller

3sum-smaller

Binary Search

Graph Valid Tree

graph-valid-tree

Breadth-First Search

Union Find

Graph

Paint House II

paint-house-ii

Palindrome Permutation

palindrome-permutation

Bit Manipulation

Palindrome Permutation II

palindrome-permutation-ii

Alien Dictionary

alien-dictionary

Topological Sort

Closest Binary Search Tree Value

closest-binary-search-tree-value

Encode and Decode Strings

encode-and-decode-strings

Closest Binary Search Tree Value II

closest-binary-search-tree-value-ii

Paint Fence

paint-fence

Find the Celebrity

find-the-celebrity

Wiggle Sort

wiggle-sort

Zigzag Iterator

zigzag-iterator

Queue

Inorder Successor in BST

inorder-successor-in-bst

Walls and Gates

walls-and-gates

Matrix

Word Pattern II

word-pattern-ii

Best Meeting Point

best-meeting-point

Math

Binary Tree Longest Consecutive Sequence

binary-tree-longest-consecutive-sequence

Smallest Rectangle Enclosing Black Pixels

smallest-rectangle-enclosing-black-pixels

Number of Islands II

number-of-islands-ii

Range Sum Query 2D - Mutable

range-sum-query-2d-mutable

Binary Indexed Tree

Segment Tree

Sparse Matrix Multiplication

sparse-matrix-multiplication

Binary Tree Vertical Order Traversal

binary-tree-vertical-order-traversal

Shortest Distance from All Buildings

shortest-distance-from-all-buildings

Generalized Abbreviation

generalized-abbreviation

Number of Connected Components in an Undirected Graph

number-of-connected-components-in-an-undirected-graph

Maximum Size Subarray Sum Equals k

maximum-size-subarray-sum-equals-k

Largest BST Subtree

largest-bst-subtree

Nested List Weight Sum

nested-list-weight-sum

Longest Substring with At Most K Distinct Characters

longest-substring-with-at-most-k-distinct-characters

Moving Average from Data Stream

moving-average-from-data-stream

Database

Counting

Linked List

Ordered Set

Enumeration

Trie

Divide and Conquer

Bitmask

Memoization

Geometry

Number Theory

Hash Function

Game Theory

Combinatorics

Shortest Path

String Matching

Rolling Hash

Brainteaser

Randomized

Monotonic Queue

Merge Sort

Concurrency

Doubly-Linked List

Probability and Statistics

Quickselect

Bucket Sort

Suffix Array

Minimum Spanning Tree

Counting Sort

Shell

Line Sweep

Reservoir Sampling

Eulerian Circuit

Radix Sort

Strongly Connected Component

Rejection Sampling

Biconnected Component