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Foundations Ladders

These ladders are the practice side of the beginner layer.

Use them after reading the corresponding tutorial pages in topics/foundations/.

Subtopic Ladders

How To Use These Ladders

  • solve a few warm-ups quickly
  • write one clean reusable implementation
  • only then move to the core or stretch bucket

The beginner layer is about fluency and recognition, not heroic single-problem grinding.

Suggested First Route

If you want a concrete path instead of browsing randomly, use:

  1. C++ language
  2. STL habits
  3. Complexity and invariants
  4. Sorting
  5. Binary search
  6. Prefix sums
  7. Difference arrays
  8. Two pointers
  9. Bit tricks
  10. Recursion and backtracking

Why this order works:

  • syntax and container choice stop being the main blocker
  • invariants and complexity checks arrive before harder scans
  • sorting and binary search teach clean ordered reasoning early
  • prefix logic prepares you for later Fenwick and segment tree topics
  • bit tricks makes packed-state notation less mysterious before bitmask-heavy topics
  • recursion/backtracking gives a clean search-tree bridge before DP and complexity triage

First Week Route

If you want the smallest workable beginner route inside this repo, do just this:

  1. read C++ language
  2. solve Weird Algorithm
  3. read Complexity and invariants
  4. solve Missing Number
  5. solve Increasing Array
  6. read Prefix sums
  7. solve Static Range Sum Queries

That is enough to build a real local loop before harder patterns.

Repo Anchors

If you want the first internal notes to open in this section, start with:

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