The recruiter emailed me, inquiring about my interest in Facebook. He likely found my email address on a programming contest site. This was a surprise email because the same recruiter had contacted me a year prior but never called, despite scheduling times on three occasions. However, this time he did call and arranged a phone interview.

I passed two phone interviews and was scheduled for a third. A few days after the third interview, I received a thank you email stating that I didn't possess the right skills for the currently open positions. Since I received this bad news after the third interview, I will elaborate on that experience.

He called precisely on time. He was aware that I had passed two rounds, and we discussed the work done at Facebook for quite some time. He emphasized his responsible position and suitability for answering in-depth questions about Facebook. His overall attitude was friendly.

After our conversation, he presented two coding questions, which I had to solve using Collabedit. The problem difficulties were easy, but after coding, he asked me to improve certain sections of the code. A requirement was that the code must compile. I was typing in a web-based editor without a compile option and am unsure if compiling code on the first attempt is considered a significant skill. From my perspective, I performed well, if not excellently.

They mentioned they would consider me when relevant positions become available. I am uncertain if this is their standard procedure for rejection emails or if they are acknowledging my positive performance in passing two phone rounds.

Write a C function to define strstr(char *haystack, char *needle) to return the first occurrence of needle in haystack. Code must compile and execute.

Write a C function to define strcmp(char *s1, char *s2) to return negative if s1 is smaller, positive if s2 is greater, and 0 if they are equal.