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
   

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2. Intermediate Software Engineering
   Week 1
   

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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

   

   

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4. U
   M
   P
   I
   R
   E
   

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5. Understand
   Match
   Plan
   Implement
   Review
   Evaluate
   

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6. Understand - Clarify what the interviewer is asking for
   Match
   Plan
   Implement
   Review
   Evaluate
   

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7. Understand - Clarify what the interviewer is asking for
   Match - Identify similar patterns
   Plan
   Implement
   Review
   Evaluate
   

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8. Understand - Clarify what the interviewer is asking for
   Match - Identify similar patterns
   Plan - Come up with algorithm, proof it works
   Implement
   Review
   Evaluate
   

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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
   

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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
    

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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
    

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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
    

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13. In Class Exercise - UMPIRE Warmup
    

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14. Return distinct values from a list including duplicates
    Given {1, 2, 6, 6, 6, 10, 14, 14} ; Return -> {1, 2, 6, 10, 14}
    

    

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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: 

    

    

    

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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?
    

    

    

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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 …? 

    

    

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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}

    

    

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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 …? 

    

    

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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}

    

    

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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 … ? 

    

    

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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}

    

    

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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?

    

    

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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: 

    

    

    

    

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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?

    

    

    

    

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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?

    

    

    

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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

    

    

    

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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

    

    

    

    

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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

    

    

    

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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 ! 

    

    

    

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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

    

    

    

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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?
    

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33. In Class Exercise - UMPIRE Warmup
    

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34. In Class Exercise - UMPIRE Warmup
    Work in groups to get more comfortable with UMPIRE
    

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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
    

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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
    

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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!

    

    

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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
    

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39. Questions?
    Did you add your group number to
    your name?? (Example: 24 - Caren )
    

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40. How’d it go?
    

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41. Before Monday midnight..
    

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42. Before Monday midnight..
    Review UMPIRE 

    guide linked in course portal

    lecture slides also linked in course portal
    

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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
    

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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
    

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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!
    

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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

    

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47. Next week
    Big O

    

    Hash Tables
    Panel!
    

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