From b73bcd6aeaa2d4b72b9f6984f44a64c9c9d1e33a Mon Sep 17 00:00:00 2001
From: Nathan van Ofwegen <nj.vanofwegen@gmail.com>
Date: Wed, 16 Dec 2020 19:06:31 +0100
Subject: [PATCH] part 1 day 15

---
 day15/day15.py  | 43 +++++++++++++++++++++++++++++++++++++++++++
 day15/input.txt |  1 +
 2 files changed, 44 insertions(+)
 create mode 100644 day15/day15.py
 create mode 100644 day15/input.txt

diff --git a/day15/day15.py b/day15/day15.py
new file mode 100644
index 0000000..adcc071
--- /dev/null
+++ b/day15/day15.py
@@ -0,0 +1,43 @@
+def part1():
+    file = open("input.txt")
+    lines = [i.strip() for i in file.readlines()]
+
+    numbers = lines[0].split(',')
+
+    history = {}
+
+    final_round = 2020
+    last_spoken = ''
+
+    for i in range(0, final_round):
+
+        if i < len(numbers):
+            print(f'Turn {i + 1}: {numbers[i]}')
+            last_spoken = numbers[i]
+            history[last_spoken] = [i]
+            continue
+
+        if len(history[last_spoken]) == 1:
+            last_spoken = '0'
+            history[last_spoken].append(i)
+        else:
+            count = len(history[last_spoken])
+            last_spoken = str(history[last_spoken][count - 1] - history[last_spoken][count - 2])
+            if last_spoken not in history:
+                history[last_spoken] = [i]
+            else:
+                history[last_spoken].append(i)
+
+        # print(f'Turn {i + 1}: {last_spoken}')
+
+    print(f"Part 1: {last_spoken}")
+
+
+def part2():
+    pass
+    # print("Part 2: ")
+
+
+if __name__ == "__main__":
+    part1()
+    part2()
diff --git a/day15/input.txt b/day15/input.txt
new file mode 100644
index 0000000..8285f9b
--- /dev/null
+++ b/day15/input.txt
@@ -0,0 +1 @@
+15,12,0,14,3,1