Practice by building

Turn C# concepts into working code

Work through 50 focused problems from loops and strings to graphs and dynamic programming. Every solution runs in one click and has been checked against the output shown.

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50problems

25beginner

25intermediate

✓50 of 50 solutions compiler verified

Complete collectionBeginner → Intermediate

50 C# coding problems

Each exercise gives you a clear prompt, a reasoning-first approach, time and space complexity, a complete Mono-compatible console program, and the exact output you should see.

Fundamentals

Numbers, strings, arrays, and matrices

Core patterns

Two pointers, stacks, hash lookup

Algorithms

Sorting, recursion, trees, and graphs

Problem solving

Backtracking and dynamic programming

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