Mistakes of C code made by novices

These are collections of memory mistakes made by students in their C code.

Contributions are welcome.

The contribution guidelines:

1. Obtain the entire source code for each mistake
2. Use https://cee.studio to create an executable demo link^*
3. Describe briefly each mistake
4. Include the original post link (if it's possible)

Memory Errors

* The included code can compile and generate an executable