Discussion 0: Getting Started

This is an online worksheet that you can work on during discussions. Your work is not graded and you do not need to submit anything.

Lost on the Moon

Your spaceship has just crashed on the light side of the moon. You were scheduled to rendezvous with a mother ship 200 miles away on the lighted surface of the moon, but the rough landing has ruined your ship and destroyed all the equipment on board except for the 15 items listed below. (Note: you are able to consume food/water/medicine inside your space suit).

Your crew's survival depends on reaching the mother ship, so you must choose the most critical items available for the 200-mile trip. Your task is to rank the 15 items in terms of their importance for survival. Place a number 1 by the most important item, number 2 by the second most important, and so on, through number 15, the least important.

Item Your Rank (1) Group's Rank (2) NASA's Rank (3) | (3) - (1) | | (3) - (2) |
Box of matches
Food concentrate
50 feet of nylon rope
Parachute silk
Solar-powered portable heating unit
Two .45 caliber pistols
One case of dehydrated milk
Two 100-pound tanks of oxygen
Stellar map (of the moon's constellations)
Self-inflating life raft
Magnetic compass
5 gallons of water
Signal flares
First-aid kit containing injection needles
Solar-powered FM receiver-transmitter
Error points are the absolute difference between your rankings and NASA's (disregard plus or minus signs).
  • 0 - 25: excellent
  • 26 - 32: good
  • 33 - 55: fair
  • 56 - 70: oops
  • 71 - 112: oh well
Item NASA's Reasoning NASA's Rank
Box of matches No oxygen to sustain flame, virtually worthless 15
Food concentrate Efficient means of supplying energy requirements 4
50 feet of nylon rope Useful in scaling cliffs, tying injured together 6
Parachute silk Protection from sun's rays 8
Solar-powered portable heating unit Not needed unless on dark side 13
Two .45 caliber pistols Possible means of self-propulsion 11
One case of dehydrated milk Bulkier duplication of food concentrate 12
Two 100-pound tanks of oxygen Most pressing survival need 1
Stellar map (of the moon's constellations) Primary means of navigation 3
Self-inflating life raft CO_2 bottle in military raft may be used for propulsion 9
Magnetic compass Magnetic field on moon is not polarized; worthless for navigation 14
5 gallons of water Replacement for tremendous liquid loss on lighted side 2
Signal flares Distress signal when mother ship is sighted 10
First-aid kit containing injection needles Needles for vitamins, medicines, etc., will fit special aperture in NASA space suits 7
Solar-powered FM receiver-transmitter For communication with mother ship; but FM requires line-of-sight transmission and short ranges 5

Secrets to Success in CS 61A

CS 61A is definitely a challenge, but we all want you to learn and succeed, so here is a collection of various tips that might help in your journey:

  • Ask questions. If you encounter something you don't know or aren't sure about a concept or problem, ask away. We're here to help you learn, and if you ask a question, that tells us where we can help with your understanding of the material. The process of asking questions itself can also be helpful in figuring out for yourself what you would specifically like to ask about, and in therefore pinpointing concepts that you believe you can learn more about.
  • Study in groups. Again, this class is not trivial; you might feel overwhelmed going at it alone. Send a message and reach out to other students in the class; work together on assignments or study together to prepare for exams, as long as you don't violate the course policy on Academic Honesty as stated in the Syllabus.
  • When stuck on a problem, try to explain the area in which you are stuck. This doesn't need to require a person who understands how to solve the problem (or even a person - this practice is often referred to as rubber ducking since you can take a rubber duck and consider it your practice audience) because the main goal is for you to clarify your own thoughts and figure out where exactly you're getting stuck with your understanding and code. From there you can focus on that portion to better your understanding.
  • If you're still feeling stuck, feel free to make use of the class Piazza (our course forum for asking and answering questions) or attend office hours.
  • Office hours gives you time with the instructors or staff by themselves, and you will be able to get some (nearly) one-on-one instruction. You are not intruding; the instructors and staff are here to help as you learn.
  • Do (or at least attempt seriously) all the homework. We do not give many homework problems, but those we do give you may find are challenging, time-consuming, and rewarding.
  • Do all the lab exercises. Most of them are designed as more of an introduction to the course material, and may take around the length of a lab section. This is a great time to get acquainted with new material. Feel free to ask the staff members in your lab section or come to office hours if you would like more guidance.
  • Optional lab questions are 'optional' in the sense that they are extra practice, not that they are material that's out of scope. Make sure you do them if you have time.
  • Do the readings before lecture. They can be helpful in offering an overview of the material covered in lecture and other aspects of the class, as well as being a reference as part of the overall textbook that you can refer to as you go through the course.
  • When preparing for the exams, do past exam questions! Lecture, lab, and discussion provide a great introduction to the material, but the main way to learn how to solve exam-level problems is to do exam-level problems. You can find past exams (and other resources) under the Resources tab of the website. Many past exams also have solutions or walkthrough videos where past staff members may walk you through the solution to the exam.