If you find a solution online, verify it using SageMath or Python before you trust it. Coding theory is unforgiving—one wrong basis vector breaks the entire proof. Why You Don’t Actually Want a Full Solution Manual Let me challenge you. If you had a perfect PDF with every answer, you would rob yourself of the most valuable part of this subject: the debugging process.
If you are taking a formal course, ask your professor for the (many instructors will provide these). If you are self-studying, join the Coding Theory Stack Exchange and post your specific roadblock.
Navigating the Error Patterns: A Guide to the Solution Manual for Ling & Xing’s Coding Theory