C++ STL Tricks
- Graphs
Graph Initializationint totalIslands = 0;m = grid.size(), n = grid[0].size();vector<vector<int>> visited(m,vector<int> (n,'0'));The best DSA roadmap is not the longest one. It is the one that teaches the next idea just before you need it. Start with scan-based problems, then learn recursion, trees, graphs, and DP.
Recommended Order
| Phase | Topics | Outcome |
|---|---|---|
| 1 | Arrays, Strings, Hashing | Fast lookup and clean scans |
| 2 | Binary Search, Sorting, Stack/Queue | Boundaries and monotonic state |
| 3 | Linked List, Recursion, Backtracking | Pointer and recursive thinking |
| 4 | Trees, Graphs | Traversal and visited-state control |
| 5 | DP, Heap, Greedy | Optimization and priority decisions |
| 6 | Bits, Math, Trie, Advanced DS | Specialized interview patterns |
Weekly Plan
Spend the first half of each week learning patterns and the second half solving mixed practice. Keep a wrong-answer log with the exact missed invariant.
FAQs
Can beginners start with DP?
They can, but it is better after recursion and arrays because DP is mostly disciplined state reuse.
How should I revise?
Use the DSA course quizzes after every topic and revisit failed questions after two days.