From 0e8e49af605d3160645e773fdec53b7cf60cc068 Mon Sep 17 00:00:00 2001
From: Tomasz Kramkowski <tk@the-tk.com>
Date: Thu, 25 Nov 2021 22:33:45 +0000
Subject: more solutions

---
 20/solution.c  | 19 ++++++++++--
 21/solution.py | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 22/solution.py |  2 ++
 3 files changed, 109 insertions(+), 3 deletions(-)
 create mode 100644 21/solution.py
 create mode 100644 22/solution.py

diff --git a/20/solution.c b/20/solution.c
index cf61687..73beb80 100644
--- a/20/solution.c
+++ b/20/solution.c
@@ -16,9 +16,8 @@ long part1(long input)
 	long *houses = emalloc(sizeof(long) * input / 10);
 	#pragma omp parallel for
 	for (long i = 1; i < input / 10; i++)
-		for (long j = i; j < input / 10; j++)
+		for (long j = i; j < input / 10; j += i)
 			houses[j] += i * 10;
-	puts("filled houses");
 	for (long i = 1; i < input / 10; i++) {
 		if (houses[i] >= input) {
 			res = i;
@@ -31,11 +30,25 @@ long part1(long input)
 
 long part2(long input)
 {
-	return -1;
+	long res = -1;
+	long *houses = emalloc(sizeof(long) * input / 10);
+	#pragma omp parallel for
+	for (long i = 1; i < input / 10; i++)
+		for (long j = i, k = 0; j < input / 10 && k < 50; j += i, k++)
+			houses[j] += i * 11;
+	for (long i = 1; i < input / 10; i++) {
+		if (houses[i] >= input) {
+			res = i;
+			break;
+		}
+	}
+	free(houses);
+	return res;
 }
 
 int main(void)
 {
 	long input = 33100000;
 	printf("%ld\n", part1(input));
+	printf("%ld\n", part2(input));
 }
diff --git a/21/solution.py b/21/solution.py
new file mode 100644
index 0000000..51bf19c
--- /dev/null
+++ b/21/solution.py
@@ -0,0 +1,91 @@
+from math import ceil
+from dataclasses import dataclass
+
+@dataclass
+class Item:
+    cost: int
+    damage: int
+    armour: int
+
+weapons = [
+    Item(8, 4, 0),
+    Item(10, 5, 0),
+    Item(25, 6, 0),
+    Item(40, 7, 0),
+    Item(74, 8, 0),
+]
+
+armour = [
+    Item(0, 0, 0),
+    Item(13, 0, 1),
+    Item(31, 0, 2),
+    Item(53, 0, 3),
+    Item(75, 0, 4),
+    Item(102, 0, 5),
+]
+
+rings = [
+    Item(0, 0, 0),
+    Item(25, 1, 0),
+    Item(50, 2, 0),
+    Item(100, 3, 0),
+    Item(20, 0, 1),
+    Item(40, 0, 2),
+    Item(80, 0, 3),
+]
+
+@dataclass
+class Player:
+    hit_points: int
+    damage: int
+    armour: int
+
+def damage_dealt(by: Player, to: Player) -> int:
+    return max(1, by.damage - to.armour)
+
+def part1(opponent: Player) -> int:
+    min_cost = float('inf')
+
+    for weapon in weapons:
+        for a in armour:
+            for ring1 in rings:
+                for ring2 in rings:
+                    if ring1 == ring2:
+                        continue
+
+                    player = Player(100, weapon.damage + ring1.damage + ring2.damage, a.armour + ring1.armour + ring2.armour)
+
+                    pturns = ceil(opponent.hit_points / damage_dealt(by=player, to=opponent))
+                    oturns = ceil(player.hit_points / damage_dealt(by=opponent, to=player))
+
+                    if pturns <= oturns:
+                        min_cost = min(min_cost, weapon.cost + a.cost + ring1.cost + ring2.cost)
+
+    return min_cost
+
+
+def part2(opponent: Player) -> int:
+    max_cost = 0
+
+    for weapon in weapons:
+        for a in armour:
+            for ring1 in rings:
+                for ring2 in rings:
+                    if ring1 == ring2:
+                        continue
+
+                    player = Player(100, weapon.damage + ring1.damage + ring2.damage, a.armour + ring1.armour + ring2.armour)
+
+                    pturns = ceil(opponent.hit_points / damage_dealt(by=player, to=opponent))
+                    oturns = ceil(player.hit_points / damage_dealt(by=opponent, to=player))
+
+                    if pturns > oturns:
+                        max_cost = max(max_cost, weapon.cost + a.cost + ring1.cost + ring2.cost)
+
+    return max_cost
+
+if __name__ == '__main__':
+    opponent = Player(103, 9, 2)
+
+    print(part1(opponent))
+    print(part2(opponent))
diff --git a/22/solution.py b/22/solution.py
new file mode 100644
index 0000000..2859416
--- /dev/null
+++ b/22/solution.py
@@ -0,0 +1,2 @@
+if __name__ == '__main__':
+    with open('input') as f:
\ No newline at end of file
-- 
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