# Special Topics

- [Meeting Hours Optimization](/unofficialsendoh/c/u/meeting-hours-optimization.md)
- [3 Ways to Implement Factory Pattern](/unofficialsendoh/c/u/3-ways-to-implement-factory-pattern.md)
- [Implement a Max Heap Using Dynamic Array](/unofficialsendoh/c/u/implementheap.md)
- [Implement Shared Pointer](/unofficialsendoh/c/u/implement-shared-pointer.md)
- [Circular Reference and Weak Pointer](/unofficialsendoh/c/u/circular-reference-and-weak-pointer.md)
- [ID Allocator](/unofficialsendoh/c/u/id-allocator.md)