# CS50 Section. Week 4. 10/6/15.
*Tuesdays 7:00-8:30pm, Science Center 309A*

> Neel Mehta  
> neelmehta@college.harvard.edu  
> (215) 990-6434

Get these handouts at <https://github.com/hathix/cs50-section/tree/master/handouts>.

# Quiz 0

Check out the handout from our Quiz 0 Review: <https://github.com/hathix/cs50-section/blob/master/handouts/quiz0-review.md>.

# Recursion



# Pointers

# Recursion && Pointers

## strlen (Fall 2013 Quiz 0)

Suppose that you've also forgotten which header file declares `strlen`, and so you need to re-implement it yourself (even if you didn't just use it). Bah. Even worse, neither `[` nor `]` currently works on your keyboard (or pencil or pen).  Without calling any functions at all  and without using any square brackets, complete the implementation of `strlen` below  using pointer arithmetic in such a way that the function returns the length of `s`. If `s` happens to be `NULL`, your implementation of `strlen` should return 0.

Solution: <http://cdn.cs50.net/2013/fall/quizzes/0/key0.pdf>.

```c
int strlen(char* s)
{

























}
```


# File I/O

Add outline of section 5
Add outline of section 5
