CodePath SE102 - Week 1b

Transcript

1. Prepend your name with your group number! 
 Example: 24

   - Caren Check our Slack channel for detailed instructions including your group number Also add a profile picture for Slack if you haven’t already

2. Intermediate Software Engineering Week 1

3. Common interview mistakes: • not communicating with interviewer • doesn’t

   catch or can’t fix bugs • speed - interviewer wasn’t able to get a good signal
 


4. U M P I R E

5. Understand Match Plan Implement Review Evaluate

6. Understand - Clarify what the interviewer is asking for Match

   Plan Implement Review Evaluate

7. Understand - Clarify what the interviewer is asking for Match

   - Identify similar patterns Plan Implement Review Evaluate

8. Understand - Clarify what the interviewer is asking for Match

   - Identify similar patterns Plan - Come up with algorithm, proof it works Implement Review Evaluate

9. Understand - Clarify what the interviewer is asking for Match

   - Identify similar patterns Plan - Come up with algorithm, proof it works Implement - Code Review Evaluate

10. Understand - Clarify what the interviewer is asking for Match

    - Identify similar patterns Plan - Come up with algorithm, proof it works Implement - Code Review - Test solution works as expected Evaluate

11. Understand - Clarify what the interviewer is asking for Match

    - Identify similar patterns Plan - Come up with algorithm, proof it works Implement - Code Review - Test solution works as expected Evaluate - Analyze run time and space complexity

12. Understand - Clarify what the interviewer is asking for Match

    - Identify similar patterns Plan - Come up with algorithm, proof it works Implement - Code Review - Test solution works as expected Evaluate - Analyze run time and space complexity

13. In Class Exercise - UMPIRE Warmup

14. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} 


15. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Understand: 
 
 


16. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Understand: 
 - is the input always sorted for us?
 - are inputs always only integers? 
 


17. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Understand: 
 - is the input always sorted for us?
 - are inputs always only integers? - Given {1, 1, 1} ; Return …? 
 


18. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Understand: 
 - is the input always sorted for us?
 - are inputs always only integers? - Given {1, 1, 1} ; Return {1}
 


19. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Understand: 
 - is the input always sorted for us?
 - are inputs always only integers? - Given {1, 1, 1} ; Return {1}
 - Given {1, 2, 3} ; Return …? 
 


20. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Understand: 
 - is the input always sorted for us?
 - are inputs always only integers? - Given {1, 1, 1} ; Return {1}
 - Given {1, 2, 3} ; Return {1, 2, 3}
 


21. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Understand: 
 - is the input always sorted for us?
 - are inputs always only integers? - Given {1, 1, 1} ; Return {1}
 - Given {1, 2, 3} ; Return {1, 2, 3}
 - Given {15, 6, 10, 5, 12, 6} ; Return … ? 
 


22. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Understand: 
 - is the input always sorted for us?
 - are inputs always only integers? - Given {1, 1, 1} ; Return {1}
 - Given {1, 2, 3} ; Return {1, 2, 3}
 - Given {15, 6, 10, 5, 12, 6} ; Return {15, 6, 10, 5, 12}
 


23. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Understand: 
 - is the input always sorted for us?
 - are inputs always only integers? - Given {1, 1, 1} ; Return {1}
 - Given {1, 2, 3} ; Return {1, 2, 3}
 - Given {15, 6, 10, 5, 12, 6} ; Return {15, 6, 10, 5, 12} Follow up question: does it matter what order our return list is?
 


24. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Match: 
 
 
 


25. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Match: 
 - are there any common patterns we can apply here?
 
 
 


26. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Match: 
 - are there any common patterns we can apply here?
 - coming in future sessions..
 - hash table
 - sort input first?
 
 


27. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Plan
 
 


28. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Plan: 
 - possible solutions:
 (1) iterate through array, put values in hash table, if value already exists, don't add to numsToReturn
 
 
 


29. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Plan: 
 - possible solutions:
 (1) iterate through array, put values in hash table, if value already exists, don't add to numsToReturn
 (2) sort array, add integer to numsToReturn if previous integer is not the same
 
 


30. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Implement: code up solution in repl.it ! 
 
 


31. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Review: run one or two inputs through our solution
 
 


32. Return distinct values from a list including duplicates Given {1,

    2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14} Evaluate: what’s the space / run time complexity of our solution? what tradeoffs did we have to make?

33. In Class Exercise - UMPIRE Warmup

34. In Class Exercise - UMPIRE Warmup Work in groups to

    get more comfortable with UMPIRE

35. In Class Exercise - UMPIRE Warmup Work in groups to

    get more comfortable with UMPIRE Review UMPIRE together, make sure everybody has a good understanding of what should be done at each step

36. In Class Exercise - UMPIRE Warmup Work in groups to

    get more comfortable with UMPIRE Review UMPIRE together, make sure everybody has a good understanding of what should be done at each step Review a sample problem solved with the UMPIRE method

37. In Class Exercise - UMPIRE Warmup Work in groups to

    get more comfortable with UMPIRE Review UMPIRE together, make sure everybody has a good understanding of what should be done at each step Review a sample problem solved with the UMPIRE method Create a shared document in repl.it to solve the problem together with the UMPIRE steps. Round robin status!
 


38. In Class Exercise - UMPIRE Warmup Work in groups to

    get more comfortable with UMPIRE Review UMPIRE together, make sure everybody has a good understanding of what should be done at each step Review a sample problem solved with the UMPIRE method Create a shared document in repl.it to solve the problem together with the UMPIRE steps. Round robin status!
 
 After 45 minutes, we’ll regroup and review the problem

39. Questions? Did you add your group number to your name??

    (Example: 24 - Caren )

40. How’d it go?

41. Before Monday midnight..

42. Before Monday midnight.. Review UMPIRE 
 guide linked in course

    portal
 lecture slides also linked in course portal

43. Before Monday midnight.. Review UMPIRE 
 guide linked in course

    portal
 lecture slides also linked in course portal Review solutions to our in class exercises

44. Before Monday midnight.. Review UMPIRE 
 guide linked in course

    portal
 lecture slides also linked in course portal Review solutions to our in class exercises Work on optional practice problems provided in course portal

45. Before Monday midnight.. Review UMPIRE 
 guide linked in course

    portal
 lecture slides also linked in course portal Review solutions to our in class exercises Work on optional practice problems provided in course portal Complete HackerRank assessment!

46. HackerRank Don’t stress out about it too much! Prep by

    doing optional practice problems Things you need to know for this week:
 UMPIRE
 Code tracing


47. Next week Big O
 
 Hash Tables Panel!