Solved 2015/13 P1+P2

2015/13/13.md

@@ -0,0 +1,80 @@
+## \-\-- Day 13: Knights of the Dinner Table \-\--
+
+In years past, the holiday feast with your family hasn\'t gone so well.
+Not everyone gets along! This year, you resolve, will be different.
+You\'re going to find the *optimal seating arrangement* and avoid all
+those awkward conversations.
+
+You start by writing up a list of everyone invited and the amount their
+happiness would increase or decrease if they were to find themselves
+sitting next to each other person. You have a circular table that will
+be just big enough to fit everyone comfortably, and so each person will
+have exactly two neighbors.
+
+For example, suppose you have only four attendees planned, and you
+calculate
+their potential happiness as follows:
+
+    Alice would gain 54 happiness units by sitting next to Bob.
+    Alice would lose 79 happiness units by sitting next to Carol.
+    Alice would lose 2 happiness units by sitting next to David.
+    Bob would gain 83 happiness units by sitting next to Alice.
+    Bob would lose 7 happiness units by sitting next to Carol.
+    Bob would lose 63 happiness units by sitting next to David.
+    Carol would lose 62 happiness units by sitting next to Alice.
+    Carol would gain 60 happiness units by sitting next to Bob.
+    Carol would gain 55 happiness units by sitting next to David.
+    David would gain 46 happiness units by sitting next to Alice.
+    David would lose 7 happiness units by sitting next to Bob.
+    David would gain 41 happiness units by sitting next to Carol.
+
+Then, if you seat Alice next to David, Alice would lose `2` happiness
+units (because David talks so much), but David would gain `46` happiness
+units (because Alice is such a good listener), for a total change of
+`44`.
+
+If you continue around the table, you could then seat Bob next to Alice
+(Bob gains `83`, Alice gains `54`). Finally, seat Carol, who sits next
+to Bob (Carol gains `60`, Bob loses `7`) and David (Carol gains `55`,
+David gains `41`). The arrangement looks like this:
+
+         +41 +46
+    +55   David    -2
+    Carol       Alice
+    +60    Bob    +54
+         -7  +83
+
+After trying every other seating arrangement in this hypothetical
+scenario, you find that this one is the most optimal, with a total
+change in happiness of `330`.
+
+What is the *total change in happiness* for the optimal seating
+arrangement of the actual guest list?
+
+Your puzzle answer was `733`.
+
+## \-\-- Part Two \-\-- {#part2}
+
+In all the commotion, you realize that you forgot to seat yourself. At
+this point, you\'re pretty apathetic toward the whole thing, and your
+happiness wouldn\'t really go up or down regardless of who you sit next
+to. You assume everyone else would be just as ambivalent about sitting
+next to you, too.
+
+So, add yourself to the list, and give all happiness relationships that
+involve you a score of `0`.
+
+What is the *total change in happiness* for the optimal seating
+arrangement that actually includes yourself?
+
+Your puzzle answer was `725`.
+
+Both parts of this puzzle are complete! They provide two gold stars:
+\*\*
+
+At this point, you should [return to your Advent calendar](/2015) and
+try another puzzle.
+
+If you still want to see it, you can [get your puzzle
+input](13/input).
+

2015/13/solution.py

@@ -0,0 +1,76 @@
+#!/bin/python3
+import sys,time,re
+from pprint import pprint
+sys.path.insert(0, '../../')
+from fred import list2int,get_re,nprint,lprint,loadFile,TSP
+start_time = time.time()
+
+input_f = 'input'
+
+#########################################
+#                                       #
+#              Part 1                   #
+#                                       #
+#########################################
+
+def parseInput():
+
+    inst = []
+    graph = {}
+    with open(input_f) as file:
+        for line in file:
+            inst = line.rstrip().split(' happiness units by sitting next to ')
+            t = inst[0].split(' would ')
+            inst = [t[0]] + [inst[1].replace('.','')] + [int(t[1].replace('lose ','-').replace('gain ',''))]
+            
+            if inst[0] not in graph:
+                graph[inst[0]] = []
+            #if inst[1] not in graph:
+            #   graph[inst[1]] = []
+            graph[inst[0]].append((inst[1],inst[2]))
+            #graph[inst[1]].append((inst[0],inst[2]))
+            
+    return graph
+
+def addBothWays(graph):
+    n_graph = {}
+    for _,a in enumerate(graph):
+        for b in graph[a]:
+            for c in graph[b[0]]:
+                if c[0] == a:
+                    if a not in n_graph:
+                        n_graph[a] = []
+                    n_graph[a].append((b[0],b[1]+c[1]))
+
+
+    return n_graph
+
+def part1():
+    graph = addBothWays(parseInput())
+    pprint(graph)
+    longest = 0
+    people = set(graph.keys()) 
+    for neighbors in graph.values():
+        for neighbor, _ in neighbors:
+            people.add(neighbor) 
+    for c in people:
+        route,distance = TSP(graph, c,'longest',True)
+        if longest < distance:
+            longest = distance
+    return longest
+    
+start_time = time.time()
+print('Part 1:',part1(), '\t\t', round((time.time() - start_time)*1000), 'ms')
+
+
+#########################################
+#                                       #
+#              Part 2                   #
+#                                       #
+#########################################
+def part2():
+    # Just add 'Myself' to the input file with gain of 0 towards everyone
+    return
+    
+start_time = time.time()
+print('Part 2:',part2(), '\t\t', round((time.time() - start_time)*1000), 'ms')