summertime warmup session - finish

5 files changed, 287 insertions, 0 deletions

diff --git a/2020/aoc2020-d21.py b/2020/aoc2020-d21.py
new file mode 100644
index 0000000..f6edea8
--- /dev/null
+++ b/2020/aoc2020-d21.py
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+#advent of code 2020
+#day 21
+#part 2 very similar to ticket problem from the same year
+
+ingredients = [];
+AllergyDict = dict();
+PossibleAllergens = set();
+AssignedAllergens = dict();
+
+PuzzleInput = open("21.in","r");
+for line in PuzzleInput:
+	line = line.replace("\n","");
+	FoodIngr, FoodAllr = line[:-1].split(" (contains ");
+	FoodIngr = FoodIngr.split(" ");
+	FoodAllr = FoodAllr.split(", ");
+	ingredients.extend(FoodIngr);	
+	for a in FoodAllr:
+		if a in AllergyDict:
+			AllergyDict[a].intersection_update(set(FoodIngr));
+		else:
+			AllergyDict[a] = set(FoodIngr);
+PuzzleInput.close();
+
+for al in AllergyDict:
+	print(al, AllergyDict[al]);
+	PossibleAllergens.update(AllergyDict[al]);
+
+p1 = len([i for i in ingredients if i not in PossibleAllergens]);
+print("part 1 =",p1);
+
+while len(AssignedAllergens) != len(AllergyDict):
+	#print(len(AssignedAllergens),"/", len(AllergyDict)); #in case it takes long
+	for al in AllergyDict:
+		if len(AllergyDict[al]) == 1:
+			found = AllergyDict[al].pop();
+			AssignedAllergens[al] = found;
+		else:
+			AllergyDict[al].difference_update( AssignedAllergens.values() );
+
+p2 = ",".join([AssignedAllergens[allergen] for allergen in sorted(AssignedAllergens.keys())]);
+print("part 2 =",p2);
diff --git a/2020/aoc2020-d22.py b/2020/aoc2020-d22.py
new file mode 100644
index 0000000..01b9a4c
--- /dev/null
+++ b/2020/aoc2020-d22.py
@@ -0,0 +1,74 @@
+#advent of code 2020
+#day 22
+#some problems with copying, modifying, accessing data between functions
+#had a bit of workarounds
+#Im too lazy to reduce the amount of code 
+#by including part1 and part2 in a single function
+
+def NormalCombat(player1, player2):
+	decks = dict();
+	decks[0] = player1.copy();
+	decks[1] = player2.copy(); 
+	while len(decks[0]) > 0 and len(decks[1]) > 0 :
+		card0 = decks[0].pop(0);
+		card1 = decks[1].pop(0);		
+		if card0 > card1:
+			decks[0].append(card0);
+			decks[0].append(card1);
+		elif card0 < card1:
+			decks[1].append(card1);
+			decks[1].append(card0);
+	score = 0;
+	for deck in decks:
+		if len(decks[deck]) == 0: continue;
+		for c, card in enumerate(decks[deck]):
+			score += (len(decks[deck])-c)*card
+		break;
+	return score;
+
+def RecursiveCombat(player1, player2):
+	decks = dict();
+	decks[0] = player1.copy();
+	decks[1] = player2.copy(); 
+	previoushands = dict();
+	previoushands[0] = [];
+	previoushands[1] = [];
+	while len(decks[0]) > 0 and len(decks[1]) > 0 :
+		if tuple(decks[0]) in previoushands[0] and tuple(decks[1]) in previoushands[1]:
+			return 0, None;
+		previoushands[0].append(tuple(decks[0]));
+		previoushands[1].append(tuple(decks[1]));
+		card0 = decks[0].pop(0);
+		card1 = decks[1].pop(0);
+		if card0 <= len(decks[0]) and card1 <= len(decks[1]):
+			winner, winscore = RecursiveCombat(decks[0][:card0],decks[1][:card1]);
+		elif card0 > card1:
+			winner = 0;
+		elif card0 < card1:
+			winner = 1;
+		playedcards = [card0,card1];
+		decks[winner].append(playedcards[winner]);
+		decks[winner].append(playedcards[(winner+1)%2]);
+	score = 0;
+	for deck in decks:
+		#print(decks[deck]);
+		if len(decks[deck]) == 0: continue;
+		for c, card in enumerate(decks[deck]):
+			score += (len(decks[deck])-c)*card
+		winplayer = 0 + deck;
+		break;
+	return winplayer, score;
+
+PuzzleInput = open("22.in","r").read();
+playerdata1, playerdata2 = PuzzleInput.split("\n\n");
+playerdecks = dict();
+for pi, playerdata in enumerate( [playerdata1,playerdata2] ):
+	playerdecks[pi] = [int(val) for val in playerdata.split("\n")[1:] if val != ""];
+
+p1 = NormalCombat(playerdecks[0],playerdecks[1]);
+print("part 1 =",p1);
+_, p2 = RecursiveCombat(playerdecks[0],playerdecks[1]);
+print("part 2 =",p2);
+print('''part 1 = 34664
+part 2 = 32018
+''');
diff --git a/2020/aoc2020-d23.py b/2020/aoc2020-d23.py
new file mode 100644
index 0000000..b0bb6c0
--- /dev/null
+++ b/2020/aoc2020-d23.py
@@ -0,0 +1,58 @@
+#advent of code 2020
+#day 23
+#kinda cheated, I used another guy's solution for debugging
+# https://0xdf.gitlab.io/adventofcode2020/23 (cool source btw)
+#turns out my dictionary was getting one value from input replaced 
+#which caused "cutting off" most of the other numbers 
+#also tried filling out the dictionary with all numbers
+#but I was getting confused by different indexation
+#puzzle uses (0,1mil] instead of "standard" [0,1mil)
+#also minor mistakes in substitution ordering
+PuzzleInput = open("23.in","r").read().replace("\n","");
+cups = [int(v) for v in PuzzleInput];
+
+def cupgame(cuplabels, lim, cuplim):
+	cupdict = dict();
+	for c_i in range(len(cuplabels) -1):
+		cupdict[cuplabels[c_i]] = cuplabels[c_i+1];
+	if cuplim == len(cuplabels):
+		cupdict[cuplabels[-1]] = cuplabels[0];
+	else:
+		cupdict[cuplabels[-1]] = 10;
+		for c_i in range(len(cuplabels)+1,cuplim):
+			cupdict[c_i] = c_i + 1;
+		cupdict[ cuplim ] = cuplabels[0];
+	
+	c0 = 0 + cuplabels[0];
+	for step in range(lim):
+		if step%1000000 == 0: print(step//1000000,"/",lim//1000000);
+		c1 = cupdict[c0] #,(c0+1)%(cuplim+1) +1);
+		c2 = cupdict[c1] #,(c1+1)%(cuplim+1) +1);
+		c3 = cupdict[c2] #,(c2+1)%(cuplim+1) +1);
+		cupdict[c0] = cupdict[c3] #,(c3+1)%(cuplim+1) +1);
+		d0 = c0 - 1;
+		if d0 == 0: d0 = cuplim;
+		while True:
+			if d0 not in [c1,c2,c3]: break;
+			d0 -= 1;
+			if d0 == 0: d0 = cuplim;
+		cupdict[c3] = cupdict[d0];
+		cupdict[d0] = c1;
+		c0 = cupdict[c0];
+		
+	if cuplim == len(cuplabels):
+		solution = "";
+		NextVal = 1;
+		for s in range(8):
+			NextVal = cupdict[NextVal];
+			solution += str(NextVal);
+	else:
+		solution = cupdict[1] * cupdict[cupdict[1]];
+		
+	return solution;
+
+p1 = cupgame(cups,100, len(cups));
+p2 = cupgame(cups,10000000, 1000000);
+print("part 1 =",p1);
+print("part 2 =",p2);
+
diff --git a/2020/aoc2020-d24.py b/2020/aoc2020-d24.py
new file mode 100644
index 0000000..c886be1
--- /dev/null
+++ b/2020/aoc2020-d24.py
@@ -0,0 +1,85 @@
+#advent of code 2020
+#day 24
+# https://www.redblobgames.com/grids/hexagons/
+# nested ifs in CheckAdjacent function aren't really slower than
+# making it a function, so i'm leaving it bc its more readable that way
+
+def CheckAdjacent(point, blackset):
+	black = 0;
+	py,px,pz = point;
+	for dkey in directions:
+		dx,dy,dz = directions[dkey];
+		p = (py+dy,px+dx, pz+dz);
+		if p in blackset: 
+			black += 1;
+	
+	if point in blackset:
+		if black == 0 or black > 2:
+			return False;
+		else: 
+			return True;
+	else:
+		if black == 2:
+			return True;
+		else:
+			return False;
+
+tilesteps = [];
+
+PuzzleInput = open("24.in","r")
+for line in PuzzleInput:
+	line = line.replace("\n","");
+	instructions = [];
+	i = 0;
+	while i < len(line):
+		if line[i] in ["n","s"]:
+			instructions.append(line[i:i+2]);
+			i += 2;
+		else:
+			instructions.append(line[i]);
+			i += 1;
+	tilesteps.append(instructions);
+PuzzleInput.close();
+
+directions = dict();
+directions["e"] = (1,0,-1);
+directions["w"] = (-1,0,1);
+directions["ne"] = (1,-1,0);
+directions["nw"] = (0,-1,1);
+directions["sw"] = (-1,1,0);
+directions["se"] = (0,1,-1);
+
+grid = dict();
+# 0 - white
+# 1 - black
+
+for tilestep in tilesteps:
+	p = (0,0,0);
+	for step in tilestep:
+		py,px,pz = p;
+		dy,dx,dz = directions[step];
+		p = (py+dy,px+dx, pz+dz);
+	grid[p] = ( grid.get(p,0) + 1)%2;
+
+blacks = set();
+part1 = 0;
+for g in grid:
+	if grid[g] == 1: 
+		part1 += 1;
+		blacks.add(g);
+
+print("part 1 =", part1);
+
+days = 100;
+for day in range(days):
+	NewBlacks = set();
+	for b in blacks:
+		if CheckAdjacent(b,blacks): NewBlacks.add(b);
+		for coord in directions.values():
+			n = (b[0] + coord[0],b[1] + coord[1],b[2] + coord[2]);
+			if CheckAdjacent(n,blacks): NewBlacks.add(n);
+	blacks = set();
+	blacks.update(NewBlacks);
+
+part2 = len(blacks);
+print("part 2 =", part2);
diff --git a/2020/aoc2020-d25.py b/2020/aoc2020-d25.py
new file mode 100644
index 0000000..28d1afe
--- /dev/null
+++ b/2020/aoc2020-d25.py
@@ -0,0 +1,29 @@
+#advent of code 2020
+#day 25
+#I made a mistake by thinking that subject number is an unknow
+#while in reality it actually is =7 as in puzzle description
+
+def FindNumbers(pubkey):
+	S = 7;
+	L = 0;
+	v = 1;
+	while True:
+		L += 1;
+		v *= S;
+		v = v%20201227;
+		if v == pubkey:
+			return L; #gives loop number
+
+PuzzleInput = open("25.in","r").read().split("\n");
+cardkey = int(PuzzleInput[0]);
+doorkey = int(PuzzleInput[1]);
+#encryption key is the same 
+#whether we use loop of card + subject of door
+#or loop of door + subject of card
+encryption = 1;
+for l in range(FindNumbers(cardkey)):
+	encryption *= doorkey;
+	encryption = encryption%20201227;
+
+part1 = encryption; 
+print("part 1 =", part1);