Thanksgiving Break Backlog: Tuesday Nov. 25 to Saturday Nov. 29, with a lengthy digression into game theory

1.     Thanksgiving Break: Tuesday Nov. 25 to Saturday Nov. 29

a.     Tuesday:

                                                 i.     CS section. Looked at interview problems and interesting Java shortcuts like the ternary operator.

                                               ii.     Lunch. Read awesome article on Ribbonfarm while eating Kalua pig.

                                              iii.     Went to CS honors section. Solved game theory puzzles. Given a game, we had to determine under which initial conditions the first player would win and which initial conditions the second player would win. We used the concept of mirroring (situations where a player would win by repeatedly doing the same thing as the last player) For example, there’s a large circle into which players are placing small, identical circular cans by turns.  The player to fit the last can into the circle wins. If the first player puts his can in the center, then mirrors whatever the second player does on subsequent turns by placing his can exactly across from the last player’s can across the center (so that can 1, can 2, and the central can lie in a line and can 1 and can 2 are equidistant from the central can) the overall first player is guaranteed to always have a move. This is because the situation will always be symmetric when presented to the overall second player, and any open spot available to the overall second player will have a corresponding spot on the other side where the overall first player can then place.

                                              iv.     We also used the idea of strategy stealing: If moves don’t interfere with each other (so that any move you make can only be good for your position), the first player can never lose with optimal play; only win or draw. This seems obvious, but Adam (our professor) gave us the proof: assume that the second player has a winning strategy for any given first-player move; then the first player can appropriate this strategy on the first move.

                                               v.     The larger logical framework we learned was a way to look at all the final positions in a two-player, win-or-lose game (we used Nim) and work backwards through the tree to find whether the first player wins the game or the second player wins. The player that ends the game wins, so we say that

1.     All end positions are P-positions (previous player win positions, where the previous player is the one whose turn it is not, or who has just played)

2.     Furthermore, all positions that lead to at least one P-position are N-positions (next player win positions, where the next player is the player whose turn it is). This is because if you are the player whose turn it is, and you can reach a position where the player whose turn it is not (which will be you) wins, then you make that move and win.

3.     And all positions that lead to only N-positions are P-positions, because it will be the previous player’s turn after you make a move in an N-position, where the player whose turn it is wins.

4.     Why are these definitions so hard to explain? There has to be better terminology to explain this.

                                              vi.     We wrote a program to play out a game of Nim from a given initial state, making all possible moves and yielding all possible end positions. Then our program worked backwards from these end positions using the definitions above and found all the intermediate N-positions and P-positions.

                                            vii.     We found that P-positions had the bizarre defining property (all P-positions had it and no N-positions did) that when you write out the number of pieces in each stack in binary and write these numbers on top of each other, the number of 1s in each column was even. I didn’t have time to stick around for the after-class proof, because I had to pack and head to Honors 100.

                                           viii.     I packed like a madman and went to Honors 100 lecture. I got there 10 minutes late, but didn’t miss anything of importance. A Honors student panel answered questions, which was somewhat interesting.

                                              ix.     I scrambled out of class early and headed to the Ave, where I planned to catch a bus to take me to the University Station (downtown, oddly enough), where I could get on the light rail to the airport. Worrying I wasn’t going to catch my bus, I pushed myself up the road towards 45^th street. Several blocks in, I realized it would be smarter to catch a bus at one of the nearer stops rather than go all the way up only to come back down. (In actuality this decision was fueled by fear and exhaustion.) So I stopped at one of the closer stops and asked a dude waiting there whether the 70, leaving from this stop would take me to University Station (My map said it would, but you never know). He kindly advised me to move over a block so that I could get on the 71-75, which stopped inside the station rather than above it. I did so, and after carefully analyzing the schedule at my new stop, I realized that I was on the wrong side of the street L. So I moved to the other side of the street and finally got on a bus going southward.

                                               x.     I talked to a friendly guy on the bus, who eventually helped me get off at the right place, despite displaying the mild social ineptitude and mental instability common to many riders of public transportation (myself included? J ). Read Wise Man’s Fear.

                                              xi.     Got off at the station, looked around a little bit, talked to a cop standing at the escalator, double-blunder-checked myself by noting the airplane-ready suitcases owned by the crowd waiting for the light rail, made sure to swipe my Husky Card, then boarded the light rail.

                                            xii.     I learned that the last stop was the airport and settled down (standing up clutching my suitcase at first) to read. We motored through regions of Seattle I had never seen before.

                                           xiii.     We arrived in a region of the airport I had also never seen. I followed the crowd over two skybridges, between the light rail terminal and the parking garage, and the parking garage and the airport, before arriving in terra cognita.

                                           xiv.     Mildly panicked when I realized my ticket had no gate assignment on it, before realizing I could read this off a arrival/departure board.

                                            xv.     Breezed through security before a pat-down revealed my dorm key, which I had completely forgotten I was wearing. After the genial TSA man inspected the key, he let me pass.

                                           xvi.     Ate a burrito at Qdoba.

                                         xvii.     Made my way to my gate, boarded.

                                        xviii.     Read and slept. Uneventful flight. Finished Wise Man’s Fear.

                                           xix.     Arrived in California.

                                            xx.     Waited in the wrong area for a bit before being grabbed by a smiling, barefoot, and aproned cousin and chaperoned upstairs to the waiting car.

                                           xxi.     Drove to our uncle and aunt’s house uneventfully. Discussed school with my cousin.

                                         xxii.     Stayed up for a bit chatting with everyone, then hit the hay.

b.     Rest of Thanksgiving Summary

                                                 i.     Thanksgiving went very well. A clever innovation eased the recurring family tensions by devolving responsibility for planning Thanksgiving dinner from my overworked aunt to all her sub-chefs. Usually, my aunt plans an elaborate themed dinner (last year was either French or MexiGal (Mexican/Portuguese), I don’t remember which), then we go on a shopping trip armed with pages and pages of lists. Finally, we cook all the dishes under my aunt’s watchful eye.

                                               ii.     This time, we participated in the “Thanksgiving Challenge”; we all go shopping before we know what we’re going to cook, then we pick the general dish we’re going to cook out of a hat. I got “Stuffing & Gravy”, a stressful assignment.

                                              iii.     I carried it off tolerably, browning chorizo after brushing off the concern that its top ingredient was “Pork lymph nodes”, combining with onion and lots of garlic, mixing with bread, egg, and broth, and baking. I also made a standard version without chorizo. I included apples and failed to compensate for their added moisture, which resulted in soggy traditional stuffing.

                                              iv.     The gravy was pretty tasty, though. I used turkey drippings, broth, flour, and some garlic-scallion mix to produce a creamy sauce.

                                               v.     Thanksgiving dinner was widely hailed as quite good, despite the lack of coordination and planning. My cousin had somehow engineered a crispy, moist, Parmesan-crusted turkey, and every other dish complemented it well.

                                              vi.     Beyond the dinner, we took several early-morning hikes. One led us through stunning hilly scrubland overlooking the sea. The crisp morning soon yielded to sun beating down through air as blue as the ocean below, but we managed to find refuge in a patch of shade that felt as cool as if it were air-conditioned. At one point we traversed a side trail that narrowed and filled with brush and we had to scale a spiky hillside to regain the main path, but in the side trail lay rocks that clearly bore the fossilized imprints of shells.

                                            vii.     Dad and I debated with our great-uncle, a somewhat libertarian political philosopher, as per usual.

                                           viii.     We had less time to hang out with our cousin as usual, since her job at Nordstrom’s required her to work hours in close proximity to Thanksgiving. She was very excited about this intro physiology class she was taking despite having previously shown little interest in science. We watched a lecture on neuron action potentials. Her professor was very interesting—I wasn’t sure whether I was compelled or annoyed. Every five seconds he would interrupt his very clear, well-organized lecture to emphasize the importance of a point he was making or draw the class’s attention to something. This left no room for one’s mind to explore a side tangent or wander off, a good thing or a bad thing depending on one’s perspective.

                                              ix.     Our traditional football-throwing competition was won handily by my dad. My sister and cousin wrestled me for the football and played keep-away from the guys.

                                               x.     On Saturday afternoon, we left for the airport. The journey home was orders of magnitude easier than the journey to California. I followed my family like a sheep through the familiar obstacles, slept in the car, and laid myself down for the night on a mat in my younger sister’s bedroom in Bellingham.