Practice BankHard

MANG Interview Problem Bank

A curated practice bank for turning patterns into repetition.

A structured problem bank that complements the theory tracks with representative interview-style questions across major algorithm families.

70 lessons•24 modules•416 min
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Designed for

Candidates who already know the fundamentals and need sharper repetition.

You leave with

  • A deeper bench of solved problems organized by core interview patterns
  • Faster recall under time pressure from deliberate, categorized practice
  • A stronger bridge between theory lessons and real question execution

Curriculum Map

A structured path that feels worth paying for

Every module is ordered to build confidence, not just collect content. Start with the right fundamentals, deepen into the mechanics, then pressure-test your thinking with realistic engineering trade-offs.

Module 1

Easy Array Patterns

2 lessons•12 min
1

Problem: Range Sum Query (Easy)

Easy • 6 min read

2

Problem: Move Zeroes (Easy)

Easy • 6 min read

Module 2

Easy Bit Patterns

1 lessons•6 min
1

Problem: Number of 1 Bits (Easy)

Easy • 6 min read

Module 3

Easy Graph Patterns

1 lessons•6 min
1

Problem: Flood Fill (Easy)

Easy • 6 min read

Module 4

Easy List Patterns

1 lessons•6 min
1

Problem: Linked List Cycle (Easy)

Easy • 6 min read

Module 5

Easy Search Patterns

1 lessons•6 min
1

Problem: Binary Search (Easy)

Easy • 6 min read

Module 6

Easy String Patterns

2 lessons•11 min
1

Problem: Valid Anagram (Easy)

Easy • 5 min read

2

Problem: Valid Palindrome (Easy)

Easy • 6 min read

Module 7

Easy Tree Patterns

1 lessons•5 min
1

Problem: Binary Tree In-order Traversal (Easy)

Easy • 5 min read

Module 8

Hard Array Patterns

8 lessons•42 min
1

MANG Problem #1: Trapping Rain Water (Hard)

Hard • 6 min read

2

MANG Problem #6: Sliding Window Maximum (Hard)

Hard • 6 min read

3

MANG Problem #24: Employee Free Time (Hard)

Hard • 5 min read

4

MANG Problem #26: Largest Rectangle in Histogram (Hard)

Hard • 5 min read

5

MANG Problem #27: First Missing Positive (Hard)

Hard • 5 min read

6

MANG Problem #30: Smallest Range Covering Elements from K Lists (Hard)

Hard • 5 min read

7

MANG Problem #33: Insert Interval (Hard)

Hard • 5 min read

8

MANG Problem #37: Minimum Number of K Consecutive Bit Flips (Hard)

Hard • 5 min read

Module 9

Hard Backtracking Patterns

2 lessons•11 min
1

MANG Problem #10: Sudoku Solver (Hard)

Hard • 6 min read

2

MANG Problem #12: N-Queens (Hard)

Hard • 5 min read

Module 10

Hard Binary Search

1 lessons•6 min
1

MANG Problem #2: Median of Two Sorted Arrays (Expert)

Hard • 6 min read

Module 11

Hard Design Patterns

6 lessons•35 min
1

MANG Problem #5: LRU Cache Design (Hard)

Hard • 6 min read

2

MANG Problem #16: LFU Cache Design (Hard)

Hard • 6 min read

3

MANG Problem #34: Find Median from Data Stream (Hard)

Hard • 6 min read

4

MANG Problem #39: Design Search Autocomplete System (Hard)

Hard • 6 min read

5

MANG Problem #42: Design In-Memory File System (Hard)

Hard • 5 min read

6

MANG Problem #49: Prefix and Suffix Search (Hard)

Hard • 6 min read

Module 12

Hard DP Patterns

5 lessons•27 min
1

MANG Problem #29: Burst Balloons (Hard)

Hard • 5 min read

2

MANG Problem #32: Word Break II (Hard)

Hard • 5 min read

3

MANG Problem #35: Maximum Profit in Job Scheduling (Hard)

Hard • 6 min read

4

MANG Problem #45: Maximize Score After N Operations (Hard)

Hard • 6 min read

5

MANG Problem #46: Count Vowels Permutation (Hard)

Hard • 5 min read

Module 13

Hard Graph Patterns

10 lessons•58 min
1

MANG Problem #8: Alien Dictionary (Hard)

Hard • 6 min read

2

MANG Problem #17: Word Ladder (Hard)

Hard • 5 min read

3

MANG Problem #28: Word Ladder II (Hard)

Hard • 5 min read

4

MANG Problem #40: Swim in Rising Water (Hard)

Hard • 6 min read

5

MANG Problem #41: Making A Large Island (Hard)

Hard • 6 min read

6

MANG Problem #43: Cut Off Trees for Golf Event (Hard)

Hard • 6 min read

7

MANG Problem #44: Race Car (Hard)

Hard • 6 min read

8

MANG Problem #47: Valid Arrangement of Pairs (Hard)

Hard • 6 min read

9

MANG Problem #48: Parallel Courses III (Hard)

Hard • 6 min read

10

MANG Problem #50: Sliding Puzzle (Hard)

Hard • 6 min read

Module 14

Hard List Patterns

2 lessons•10 min
1

MANG Problem #4: Merge K Sorted Lists (Hard)

Hard • 5 min read

2

MANG Problem #7: Reverse Nodes in k-Group (Hard)

Hard • 5 min read

Module 15

Hard Matrix Patterns

3 lessons•15 min
1

MANG Problem #3: Word Search II (Hard)

Hard • 5 min read

2

MANG Problem #22: Longest Increasing Path in a Matrix (Hard)

Hard • 5 min read

3

MANG Problem #25: Maximal Rectangle (Hard)

Hard • 5 min read

Module 16

Hard String Patterns

6 lessons•32 min
1

MANG Problem #11: Longest Valid Parentheses (Hard)

Hard • 5 min read

2

MANG Problem #13: Edit Distance (Hard)

Hard • 5 min read

3

MANG Problem #15: Basic Calculator II (Hard)

Hard • 5 min read

4

MANG Problem #23: Minimum Window Subsequence (Hard)

Hard • 6 min read

5

MANG Problem #31: Regular Expression Matching (Hard)

Hard • 5 min read

6

MANG Problem #38: Palindrome Pairs (Hard)

Hard • 6 min read

Module 17

Hard Tree Patterns

4 lessons•20 min
1

MANG Problem #9: Binary Tree Maximum Path Sum (Hard)

Hard • 5 min read

2

MANG Problem #14: K-th Smallest in Lexicographical Order (Hard)

Hard • 5 min read

3

MANG Problem #21: Serialize and Deserialize Binary Tree (Hard)

Hard • 5 min read

4

MANG Problem #36: Serialize and Deserialize BST (Hard)

Hard • 5 min read

Module 18

Medium Array Patterns

4 lessons•24 min
1

Problem: Container With Most Water (Medium)

Medium • 6 min read

2

Problem: 3Sum - Finding Unique Triplets

Medium • 6 min read

3

Problem: Merge Intervals

Medium • 6 min read

4

Problem: Daily Temperatures (Monotonic Stack)

Medium • 6 min read

Module 19

Medium Graph Patterns

1 lessons•6 min
1

Problem: Course Schedule (Topological Sort)

Medium • 6 min read

Module 20

Medium Matrix Patterns

1 lessons•6 min
1

Problem: Number of Islands (DFS/BFS)

Medium • 6 min read

Module 21

Medium Search Patterns

1 lessons•6 min
1

Problem: Search in Rotated Sorted Array

Medium • 6 min read

Module 22

Medium String Patterns

1 lessons•5 min
1

Problem: Group Anagrams

Medium • 5 min read

Module 23

Medium Tree Patterns

2 lessons•13 min
1

Problem: Binary Tree Level Order Traversal

Medium • 6 min read

2

Problem: Lowest Common Ancestor of a Binary Tree

Medium • 7 min read

Module 24

Practice Problems

4 lessons•48 min
1

The 'Small Files' Problem in Data Lakes: Why Your Kafka Sink is Slow

Easy • 7 min read

2

System Design: Solving the Top K Problem (Heavy Hitters)

Hard • 18 min read

3

N-Queens Problem in Java: Solving Constraints with Backtracking

Hard • 12 min read

4

Big-O Notation in Java: Time and Space Complexity for Interview Problem Solving

Easy • 11 min read