From 2c8a0124006e3f6d42f10495866a6ca772fcf413 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Jos=C3=A9=20Guti=C3=A9rrez=20de=20Quevedo=20P=C3=A9?=
 =?UTF-8?q?rez?= <juanjo@gutierrezdequevedo.com>
Date: Tue, 15 Dec 2020 11:41:46 +0100
Subject: [PATCH] add a C version of the 2 problem

I wanted to check how much faster a C version would be. As it turns out
it is *MUCH* faster, the python version takes ca. 12s, the C version
takes a few milliseconds.
---
 15/2.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 15/2.c

diff --git a/15/2.c b/15/2.c
new file mode 100644
index 0000000..f0696d6
--- /dev/null
+++ b/15/2.c
@@ -0,0 +1,31 @@
+#include <stdio.h>
+#include <stdint.h>
+
+uint32_t content[] = {2,0,6,12,1,3};
+uint32_t spoken[30000000] = {0};
+
+int main(int argc, char *argv[])
+{
+
+    uint32_t new_spoken = 0;
+    uint32_t turn = 1;
+    uint32_t last_turn = 0;
+
+    for(int i = 0; i<sizeof(content)/sizeof(uint32_t); i++, turn++)
+        spoken[content[i]] = turn;
+
+    for(;turn <= 30000000; turn++)
+    {
+        if(!last_turn)
+            new_spoken = 0;
+        else
+            new_spoken = turn - 1 - last_turn;
+
+        last_turn = spoken[new_spoken];
+        spoken[new_spoken] = turn;
+    }
+
+    printf("%d\n", new_spoken);
+
+    return 0;
+}