Key Topics to Prepair

1. Basic Data structures
1. Linked lists
2. Trees
3. Their implementation in C
2. C Concepts
1. Pointers
2. 2d, 3d arrays
3. 2d, 3d dynamic arrays
4. static, automatic variables
5. heap, stack
6. bit level operations
7. etc.
3. Algorithms
1. Sorting
2. Searching
3. Time + Space complexity
4. OS Concepts
1. memory management
2. scheduling
3. process states
4. signalling
5. IPC
1. Shared memory
2. Mutex, seamophores 
3. FIFO, pipes
4. Sockets
1. Socket options
2. blocking/non-blocking
3. select/epoll/poll
4. Packet structures
5. TCP handshaking and networking concepts
6. network routes and traceroute/ping
5. Aptitude
1. Puzzles
2. Adobe/MS interview questions.