update week 3

Author: SSQ

README.md

@@ -24,6 +24,16 @@ Notebook for quick search can be found [here](https://ssq.github.io/2017/07/17/C
  - [Motivation](https://github.com/SSQ/Coursera-Stanford-Divide-and-Conquer-Sorting-and-Searching-and-Randomized-Algorithms/blob/master/Lecture%20Slides/4.1-slides_algo-master1_typed.pdf)
  - [Example](https://github.com/SSQ/Coursera-Stanford-Divide-and-Conquer-Sorting-and-Searching-and-Randomized-Algorithms/blob/master/Lecture%20Slides/4.3-slides_algo-master3_typed.pdf)
  - [Proof I](https://github.com/SSQ/Coursera-Stanford-Divide-and-Conquer-Sorting-and-Searching-and-Randomized-Algorithms/blob/master/Lecture%20Slides/4.4-slides_algo-master4_typed.pdf), [Proof II](https://github.com/SSQ/Coursera-Stanford-Divide-and-Conquer-Sorting-and-Searching-and-Randomized-Algorithms/blob/master/Lecture%20Slides/4.6-slides_algo-master6_typed.pdf)
-- Week 3:
+
+- Week 3 Lecture slides:
+ - 5: Randomized Algorithm - QuickSort:
+ - [Overview](https://github.com/SSQ/Coursera-Stanford-Divide-and-Conquer-Sorting-and-Searching-and-Randomized-Algorithms/blob/master/Lecture%20Slides/5.1-slides_algo-qsort-intro_typed.pdf);
+ - [The Partition Subroutine](https://github.com/SSQ/Coursera-Stanford-Divide-and-Conquer-Sorting-and-Searching-and-Randomized-Algorithms/blob/master/Lecture%20Slides/5.2-slides_algo-qsort-partition_typed.pdf);
+ - [Proof](https://github.com/SSQ/Coursera-Stanford-Divide-and-Conquer-Sorting-and-Searching-and-Randomized-Algorithms/blob/master/Lecture%20Slides/5.3-slides_algo-qsort-correctness_typed.pdf);
+ - [Choosing a Good Pivot](https://github.com/SSQ/Coursera-Stanford-Divide-and-Conquer-Sorting-and-Searching-and-Randomized-Algorithms/blob/master/Lecture%20Slides/5.4-slides_algo-qsort-pivot_typed.pdf)
+ - [Implementation of QuickSort](https://github.com/SSQ/Coursera-Stanford-Divide-and-Conquer-Sorting-and-Searching-and-Randomized-Algorithms/tree/master/Programming%20Assignment%203) with 3 pivots
+ - 6: QuickSort Analysis:
+ - [the average running time of QuickSort (with random pivots)](https://github.com/SSQ/Coursera-Stanford-Divide-and-Conquer-Sorting-and-Searching-and-Randomized-Algorithms/blob/master/Lecture%20Slides/6.3-slides_algo-qsort-analysis3_typed.pdf)
+ - 7: Probability Review:
 
 - Week 4: