Solve 25 days

3 files changed, 178 insertions, 0 deletions

diff --git a/src/24/input.txt b/src/24/input.txt
new file mode 100644
index 0000000..969be90
--- /dev/null
+++ b/src/24/input.txt
@@ -0,0 +1,23 @@
+Immune System:
+2728 units each with 5703 hit points (weak to fire) with an attack that does 18 cold damage at initiative 12
+916 units each with 5535 hit points (weak to bludgeoning) with an attack that does 55 slashing damage at initiative 20
+2255 units each with 7442 hit points (weak to radiation) with an attack that does 31 bludgeoning damage at initiative 8
+112 units each with 4951 hit points (immune to cold) with an attack that does 360 fire damage at initiative 9
+7376 units each with 6574 hit points (immune to cold, slashing, fire) with an attack that does 7 bludgeoning damage at initiative 4
+77 units each with 5884 hit points (weak to slashing) with an attack that does 738 radiation damage at initiative 6
+6601 units each with 8652 hit points (weak to fire, cold) with an attack that does 11 fire damage at initiative 19
+3259 units each with 10067 hit points (weak to bludgeoning) with an attack that does 29 cold damage at initiative 13
+2033 units each with 4054 hit points (immune to cold; weak to fire, slashing) with an attack that does 18 slashing damage at initiative 3
+3109 units each with 3593 hit points with an attack that does 9 bludgeoning damage at initiative 11
+
+Infection:
+1466 units each with 57281 hit points (weak to slashing, fire) with an attack that does 58 slashing damage at initiative 7
+247 units each with 13627 hit points with an attack that does 108 fire damage at initiative 15
+1298 units each with 41570 hit points (immune to fire, bludgeoning) with an attack that does 63 fire damage at initiative 14
+2161 units each with 40187 hit points (weak to fire) with an attack that does 33 slashing damage at initiative 5
+57 units each with 55432 hit points (weak to cold) with an attack that does 1687 radiation damage at initiative 17
+3537 units each with 24220 hit points (weak to cold) with an attack that does 11 fire damage at initiative 10
+339 units each with 44733 hit points (immune to cold, bludgeoning; weak to radiation, fire) with an attack that does 258 cold damage at initiative 18
+1140 units each with 17741 hit points (weak to bludgeoning; immune to fire, slashing) with an attack that does 25 fire damage at initiative 2
+112 units each with 44488 hit points (weak to bludgeoning, radiation; immune to cold) with an attack that does 749 radiation damage at initiative 16
+2918 units each with 36170 hit points (immune to bludgeoning; weak to slashing, cold) with an attack that does 24 radiation damage at initiative 1
diff --git a/src/24/notes.txt b/src/24/notes.txt
new file mode 100644
index 0000000..c81d665
--- /dev/null
+++ b/src/24/notes.txt
@@ -0,0 +1,26 @@
+infection and immune sys are armies
+    - made of groups of identical units
+    - group:
+        - same hitpoint
+        - same attack damage
+        - same initiative (who attacks first has highest)
+        - same weaknesses / immunities
+        - effective power = n of members * attack damage
+
+target selection:
+    - highest effective power chooses first sorted
+    if tie => higher initiative chooses first
+    - choose group it would damage most
+    if tie => largest effective power
+    if tie => largest intiative
+    if no group => no attack
+
+attack:
+    - attack in descending order of initiative
+    - regardless of army
+    - immune: 0 dmg
+    - weak: 2 x dmg
+    - only full death, units dont have dynamic health
+
+
+(army, # of units, # of hp, initiative, dict of weaknesses / immunity, damage, type)
diff --git a/src/24/solve.py b/src/24/solve.py
new file mode 100644
index 0000000..020af79
--- /dev/null
+++ b/src/24/solve.py
@@ -0,0 +1,129 @@
+from sys import argv as args

+

+sinput = open("input.txt").read()

+

+immunesys = 0

+infection = 1

+ctype = 0

+

+# parse input from file

+def parseInput():

+    groups = list()

+    for l in sinput.split("\n"):

+        pl = parseLine(l)

+        if pl != None:

+            groups.append(pl)

+    return groups

+

+# parse line of input

+def parseLine(line):

+    global ctype

+    group = None

+    if "Immune" in line:

+        ctype = immunesys

+    elif "Infection" in line:

+        ctype = infection

+    elif line != "":

+        ls = line.split()

+        group = dict()

+        group["type"] = ctype

+        group["units"] = int(ls[0])

+        group["unithp"] = int(ls[4])

+        group["initiative"] = int(ls[-1])

+        group["weak"] = list()

+        group["immune"] = list()

+        if "(" in line:

+            parenthstr = line.split("(")[1].split(")")[0]

+            traits = parenthstr.split(";")

+            for traitstr in traits:

+                info = traitstr.split()

+                group[info[0]] = [v.replace(",","") for v in info[2:]]

+        dmginfo = line.split("does")[1].split("damage")[0].split()

+        group["dmg"] = int(dmginfo[0])

+        group["dmgtype"] = dmginfo[1]

+    return group

+

+def getEffectivePower(g):

+    return g["units"] * g["dmg"]

+

+def getDamage(attacker, defender):

+    dmg = getEffectivePower(attacker)

+    dmg *= (0 if attacker["dmgtype"] in defender["immune"] else 1)

+    dmg *= (2 if attacker["dmgtype"] in defender["weak"] else 1)

+    return dmg

+

+groups = parseInput()

+

+def fight():

+    global groups

+

+    lunits = 0

+

+    immalive = len([g for g in groups if g["type"] == immunesys])

+    infalive = len([g for g in groups if g["type"] == infection])

+

+    while immalive > 0 and infalive > 0:

+        # target selection

+        attacked = list()

+        attackpairs = list()

+        groups = sorted(groups, key = lambda x : (getEffectivePower(x), x["initiative"]), reverse = True)

+        for group in groups:

+            # choose group of other army, which is not already being attacked and sort appropriately

+            enemies = [g for g in groups if g["type"] != group["type"] and g not in attacked]

+            if len(enemies) == 0:

+                continue

+            target = max(enemies, key = lambda x : (getDamage(group, x), getEffectivePower(x), x["initiative"]))

+            if getDamage(group, target) != 0: # enemies which arent immune

+                attacked.append(target)

+                attackpairs.append((groups.index(group), groups.index(target)))

+

+        # attacking phase

+        attackpairs = sorted(attackpairs, key = lambda x : groups[x[0]]["initiative"], reverse = True)

+

+        for ap in attackpairs:

+            attacker = groups[ap[0]]

+            attacked = groups[ap[1]]

+            if attacker["units"] > 0 and attacked["units"] > 0: # if attacker or defender is dead, no need to attack

+                dmg = getDamage(attacker, attacked)

+                attacked["units"] = max(0, attacked["units"] - dmg // attacked["unithp"]) # remove whole numbers of units

+

+        groups = [g for g in groups if g["units"] > 0]

+        immalive = sum([g["units"] for g in groups if g["type"] == immunesys])

+        infalive = sum([g["units"] for g in groups if g["type"] == infection])

+        units = immalive + infalive

+        if units == lunits:

+            return units

+        lunits = units

+    return units

+

+def solve1():

+    print(fight())

+

+def solve2():

+    global groups

+

+    immunewin = False

+    boost = 1

+    while not immunewin:

+        groups = parseInput()

+        for g in groups:

+            if g["type"] == immunesys:

+                g["dmg"] += boost

+

+        fight()

+

+        immunewin = (sum([0 if g["type"] == immunesys else 1 for g in groups]) == 0)

+

+        boost += 1

+

+    #print("boost:", boost)

+    print("units:", sum([v["units"] for v in groups]))

+

+def main():

+    if len(args) > 1:

+        if args[1] == "1":

+            solve1()

+        elif args[1] == "2":

+            solve2()

+

+main()