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Raymond's Learning Path

Everything we have covered, in the order we covered it. Each lesson links to the pages that explain it, and to the problem set that practised it.

Timeline

Date Lesson What we covered Read Problem set
01-16 From Bronze to Silver: overview slides Python custom sorting, prefix sums, difference arrays, sliding window, binary search on the answer, DFS flood fill, BFS shortest path Python for CP
Sorting & Greedy
DFS (Flood Fill)
BFS
01-23 First problem sets Set 1 and Set 2: binary search on the answer, first Codeforces submissions Complexity & Constraints
Binary Search
USACO-Raymond-1 (1/6)
2-BinarySearch (4/6)
01-26 Two pointers Set 3: windows, opposite ends, binary search on the answer (Hamburgers) Two Pointers & Sliding Window 3-TwoPointers (5/6)
02-10 Mixed practice Set 4: prefix sums, sorting + binary search, simulation Complexity & Constraints
Prefix Sum
4-Misc (7/10)
02-22 Algorithm map and graph theory intro Overview of two pointers / binary search / prefix sums / DP / graphs; DFS and BFS introduced Graph Concepts
DFS (Flood Fill)
5-Graph (10/16)
03-22 Graph modelling, trees, diameter Connected graph, degree, tree, leaf, reasoning from the leaves, tree diameter by two searches Graph Concepts
Tree Diameter
03-29 Adjacency lists and sets Adjacency list, Python set and its costs, deleting edges, tree properties, unicyclic graphs Storage & Traversal
Graph Concepts
04-12 BFS and backtracking BFS shortest paths with path recovery, grid BFS, knight moves, 4/8-queens with backtracking BFS
Backtracking
05-03 Dijkstra Heap Dijkstra, shortest path tree (Paths and Trees), roads vs trains (Jzzhu and Cities) Shortest Paths (Dijkstra)
05-10 DSU and Kruskal Union-find with path compression and union by size, minimum spanning tree DSU & Kruskal 6-DSU (4/8)
05-17 DSU practice Learning Languages, News Distribution with DSU DSU & Kruskal
05-31 Homework review, 2D prefix sums Make It Connected review; 2D prefix sum (OJ P1101) Prefix Sum
06-07 Difference arrays Range updates, Karen and Coffee, Covered Points Count, Counting Rectangles Difference Array
Prefix Sum
7-Intervals (5/8)
06-14 bisect bisect_left / bisect_right for counting in sorted lists Binary Search
06-21 Introduction to DP States and transitions, counting stairs, memoized recursion DP Basics
06-28 DP practice AtCoder EDU DP A–E, Set 8 DP Basics
Knapsack
8-dp-1 (0/3)
07-05 DP on graphs and grids EDU DP G Longest Path, H Grid 1 Topological Sort
LCS
07-12 DP recap, LCS, topological sort LCS table and reconstruction, Kahn's algorithm LCS
Topological Sort
07-19 Knapsack 0/1, unbounded and bounded knapsack Knapsack 9-Jun19 (3/3)
07-26 Prefix-sum templates Writing PrefixSum classes, prefix counts on strings (Set 10) Prefix Sum 10-prefixsum (2/9)
08-24 Sums of Segments Prefix sums of prefix sums + binary search editorial; difference array review Prefix Sum
Difference Array
Binary Search
08-30 Templates homework Alternating String; build PrefixSum.py and DifferenceArray.py from memory Prefix Sum
Difference Array
09-06 Two pointers review Set 11: Cellular Network, They Are Everywhere, Quiz Master Two Pointers & Sliding Window 11-TwoPointers(review) (0/5)

Topics by area

Problem sets

Dates come from submission history.

# Set Period Solved Avg. Rating
1 USACO-Raymond-1 2026-01-23 ~ 2026-01-23 1/6 1100
2 2-BinarySearch 2026-01-24 ~ 2026-01-25 4/6 1133
3 3-TwoPointers 2026-01-26 ~ 2026-02-04 5/6 1283
4 4-Misc 2026-02-10 ~ 2026-02-14 7/10 1070
5 5-Graph 2026-03-05 ~ 2026-05-21 10/16 1619
6 6-DSU 2026-05-15 ~ 2026-05-30 4/8 1588
7 7-Intervals 2026-06-02 ~ 2026-06-23 5/8 1675
8 8-dp-1 2026-06-27 ~ 2026-07-12 0/3 1367
9 9-Jun19 2026-07-21 ~ 2026-07-21 3/3
10 10-prefixsum 2026-07-31 ~ 2026-09-06 2/9 1622
11 11-TwoPointers(review) 2026-09-07 ~ 2026-09-12 0/5 1660

11 problem sets, 80 problems, 41 solved.

Credits & licenses

This is a free, non-commercial study resource. Some pages borrow figures, explanations or problem choices from OI Wiki (CC BY-SA 4.0) and USACO Guide (CC BY-NC-SA 4.0). Each page lists exactly what was borrowed, from which module and authors, and what was changed; borrowed parts keep their original license.