Study Schedule

FLEXIBLE TIMELINE

This schedule assumes a weekend sprint --- Saturday and Sunday, roughly 8 hours each. If you have more time, spread it out. If you have less, prioritize Tier 1 (Graphs) and Tier 2 (Trees) above everything else.

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Saturday --- 8 Hours

Goal: Master Graphs (all 8 problems) and start Trees.

Time	Block	Focus	Problems	Goal
9:00 -- 10:00	Morning 1	Graphs: BFS/DFS	#1 Number of Islands, #2 Course Schedule	Master grid BFS and topological sort
10:00 -- 11:00	Morning 2	Graphs: Topo Sort	#3 Course Schedule II, #4 Word Ladder	Lock in Kahn's algorithm and BFS shortest path
11:00 -- 12:00	Morning 3	Graphs: Advanced	#5 Clone Graph, #6 Network Delay Time	DFS + HashMap cloning, Dijkstra's
12:00 -- 1:00	Lunch	Break	---	Eat, walk, rest your brain
1:00 -- 2:00	Afternoon 1	Graphs: Multi-source	#7 Rotting Oranges, #8 Pacific Atlantic	Multi-source BFS, reverse-direction DFS
2:00 -- 3:00	Afternoon 2	Trees: Core	#9 Binary Tree Max Path Sum, #10 LCA of BST	Tree DP pattern, BST property exploitation
3:00 -- 4:00	Afternoon 3	Trees: LCA + Serialize	#11 LCA of Binary Tree, #12 Serialize/Deserialize BT	Recursive LCA, BFS serialization
4:00 -- 4:30	Break	Rest	---	Step away from the screen
4:30 -- 5:30	Evening 1	Trees: Validate + Diameter	#13 Validate BST, #14 Diameter of Binary Tree	Inorder/bounds technique, post-order DFS
5:30 -- 6:30	Evening 2	Review	Re-solve 2--3 problems you struggled with	Solidify weak spots before moving on

END OF SATURDAY CHECKPOINT

By end of Saturday, you should be able to write BFS, DFS, Topological Sort, and Dijkstra's from memory. If you cannot, spend the first 30 minutes of Sunday morning re-doing Graph templates before moving on.

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Sunday --- 8 Hours

Goal: Cover all remaining categories and run 2 timed mocks.

Time	Block	Focus	Problems	Goal
9:00 -- 10:00	Morning 1	Sliding Window	#15 Longest Substring Without Repeating, #16 Minimum Window Substring	Master the expand/shrink template
10:00 -- 11:00	Morning 2	Sliding Window + DP	#17 Sliding Window Maximum, #18 Longest Repeating Char Replacement	Monotonic deque, sliding window variant
11:00 -- 12:00	Morning 3	DP: 1D	#19 Coin Change, #20 LIS, #21 House Robber	Lock in 1D DP pattern and transitions
12:00 -- 1:00	Lunch	Break	---	Eat, walk, decompress
1:00 -- 2:00	Afternoon 1	DP: 2D + Memo	#22 Unique Paths, #23 Longest Increasing Path in Matrix	Grid DP and DFS + memoization
2:00 -- 3:00	Afternoon 2	HashMap + Heap	#24 Group Anagrams, #25 Top K Frequent, #26 Merge K Sorted Lists	Grouping pattern, min-heap usage
3:00 -- 4:00	Afternoon 3	Binary Search	#27 Search in Rotated Sorted Array, #28 Find Peak Element, #29 Kth Largest	Binary search edge cases, quickselect
4:00 -- 4:30	Break	Rest	---	Clear your head before strings and mocks
4:30 -- 5:15	Evening 1	Strings	#30 Implement Trie, #31 Expressive Words, #32 Word Search	Trie implementation, two-pointer, backtracking
5:15 -- 6:00	Evening 2	Timed Mock 1	Pick a problem you have not seen before	45 minutes, plain text editor (no IDE), talk out loud
6:00 -- 6:45	Evening 3	Timed Mock 2	Pick another unseen problem	Same rules. Practice the full interview flow
6:45 -- 7:30	Evening 4	Review	Review both mocks, re-read Templates	Identify remaining gaps

TIMED MOCK RULES

1. Use a plain text editor (no IDE) --- no syntax highlighting, no autocomplete, no running code
2. Set a 45-minute timer
3. Talk out loud as if an interviewer is listening
4. Follow the full flow: clarify, brute force, optimal, code, dry run, complexity
5. After time is up, check your solution against the LeetCode editorial

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Day Before the Interview

PRE-INTERVIEW CHECKLIST

This is NOT a day for new problems. This is a day for consolidation and confidence.

• Re-solve 2--3 problems you struggled with --- especially any where you needed to look at the walkthrough
• Review all templates --- read through the Templates page end to end. Can you write BFS, sliding window, and topo sort from memory?
• Do 1 timed mock --- 45 minutes, plain text editor, talk out loud
• Review the Interview Day checklist --- read the minute-by-minute breakdown and communication phrases
• Prepare your environment --- quiet room, stable internet, water bottle, pen and paper
• Get 7--8 hours of sleep --- a rested brain solves problems faster than a brain that crammed until 2 AM

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Hourly Approach for Each Problem

Use this flow for every single problem during your prep:

[0:00 - 0:02]  READ the problem statement carefully
                - What are the inputs? What are the outputs?
                - What are the constraints (array size, value range)?

[0:02 - 0:04]  BRUTE FORCE
                - What is the simplest approach, even if it is O(n^2) or worse?
                - State it clearly: "Brute force: check every pair, O(n^2)."

[0:04 - 0:09]  IDENTIFY PATTERN
                - Does this match a known template? (BFS, sliding window, DP, etc.)
                - What is the optimal time complexity I should aim for?
                - Plan your approach before writing code.

[0:09 - 0:24]  CODE THE SOLUTION
                - Write clean code with good variable names.
                - Use helper functions if logic is complex.
                - Handle edge cases (empty input, single element, etc.).

[0:24 - 0:29]  DRY RUN + DEBUG
                - Walk through a small example by hand.
                - Check off-by-one errors, boundary conditions.
                - Fix any bugs you find.

[0:29 - 0:30]  COMPLEXITY ANALYSIS
                - State time and space complexity.

STUCK AFTER 10 MINUTES?

If you have been staring at a problem for 10 minutes with no progress, look at the walkthrough on the tier page. The goal is to learn the pattern, not to suffer. Read the approach, close it, and code the solution yourself from memory.

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Progress Tracker

Check off each problem as you complete it. Be honest --- only check it off if you can solve it without looking at the solution.

Tier 1: Graphs

#	Problem	LC	Done	Confident?
1	Number of Islands	200	[ ]	[ ]
2	Course Schedule	207	[ ]	[ ]
3	Course Schedule II	210	[ ]	[ ]
4	Word Ladder	127	[ ]	[ ]
5	Clone Graph	133	[ ]	[ ]
6	Network Delay Time	743	[ ]	[ ]
7	Rotting Oranges	994	[ ]	[ ]
8	Pacific Atlantic Water Flow	417	[ ]	[ ]

Tier 2: Trees

#	Problem	LC	Done	Confident?
9	Binary Tree Max Path Sum	124	[ ]	[ ]
10	Lowest Common Ancestor BST	235	[ ]	[ ]
11	Lowest Common Ancestor BT	236	[ ]	[ ]
12	Serialize/Deserialize BT	297	[ ]	[ ]
13	Validate BST	98	[ ]	[ ]
14	Diameter of Binary Tree	543	[ ]	[ ]

Tier 3: Sliding Window

#	Problem	LC	Done	Confident?
15	Longest Substring Without Repeating	3	[ ]	[ ]
16	Minimum Window Substring	76	[ ]	[ ]
17	Sliding Window Maximum	239	[ ]	[ ]
18	Longest Repeating Char Replacement	424	[ ]	[ ]

Tier 4: Dynamic Programming

#	Problem	LC	Done	Confident?
19	Coin Change	322	[ ]	[ ]
20	Longest Increasing Subsequence	300	[ ]	[ ]
21	House Robber	198	[ ]	[ ]
22	Unique Paths	62	[ ]	[ ]
23	Longest Increasing Path in Matrix	329	[ ]	[ ]

Tier 5: HashMap / Heap / Binary Search

#	Problem	LC	Done	Confident?
24	Group Anagrams	49	[ ]	[ ]
25	Top K Frequent Elements	347	[ ]	[ ]
26	Merge K Sorted Lists	23	[ ]	[ ]
27	Search in Rotated Sorted Array	33	[ ]	[ ]
28	Find Peak Element	162	[ ]	[ ]
29	Kth Largest Element	215	[ ]	[ ]

Tier 6: Strings

#	Problem	LC	Done	Confident?
30	Implement Trie	208	[ ]	[ ]
31	Expressive Words	809	[ ]	[ ]
32	Word Search	79	[ ]	[ ]

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PROGRESS MILESTONES

• 8 problems done (all Graphs): You can handle the most common SDE interview question type.
• 14 problems done (+ Trees): You have covered the top 2 tiers. Most candidates stop here and still do well.
• 23 problems done (+ SW + DP): You are better prepared than 90% of candidates.
• 32 problems done (all): Maximum coverage. Spend remaining time on mocks.