diff --git a/day11/c/day11 b/day11/c/day11
new file mode 100755
index 0000000..0417e22
Binary files /dev/null and b/day11/c/day11 differ
diff --git a/day11/c/day11.c b/day11/c/day11.c
new file mode 100644
index 0000000..ba416b3
--- /dev/null
+++ b/day11/c/day11.c
@@ -0,0 +1,131 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define MAX_CHARS 1024
+#define MAX_INITIAL_STONES 1024
+#define MAX_LEAF_COUNT 16
+
+typedef struct stone {
+    uint64_t value;
+    struct stone *prev;
+    struct stone *next;
+} stone_t;
+
+void deallocate_ll(stone_t *leaf);
+void iterate_ll(stone_t *, void (*cb)(stone_t*, void*), void* ctx);
+
+void display(stone_t *stone, void* ctx) {
+    printf("%lu ", stone->value);
+}
+void blink(stone_t *leaf, void* ctx);
+void count(stone_t *leaf, void* ctx);
+
+int main() {
+    char c, *p, *buf;
+
+    buf = calloc(MAX_CHARS, sizeof(buf[0]));
+    p = buf;
+
+    while ((c = getchar()) != EOF) {
+        *p++ = c;
+    }
+
+    size_t in = p - buf;
+
+    int stone_count = 0;
+    uint64_t *stones = calloc(MAX_INITIAL_STONES, sizeof(stones[0]));
+    for (size_t i = 0; i < in;) {
+        p = buf + i;
+        sscanf(p, "%lu", &stones[stone_count++]);
+        
+        do {
+            i++;
+        } while(i < in && *(buf+i) != ' ');
+        i++;
+    }
+
+    stone_t *head;
+
+    for (int i = 0; i < stone_count; i++) {
+        stone_t *stone = calloc(1, sizeof(stone[0]));
+        stone->value = stones[i];
+        if (i == 0) {
+            head = stone;
+            continue;
+        }
+        stone_t *tmp = head;
+        while(tmp->next != NULL) tmp = tmp->next;
+        tmp->next = stone;
+        stone->prev = tmp;
+    }
+
+    free(stones);
+    free(buf);
+
+    int blink_count = 75;
+    for (int i = 0; i < blink_count; i++) {
+        iterate_ll(head, blink, NULL);
+        while(head->prev != NULL) head = head->prev;
+        printf("%i\n", i);
+    }
+    uint64_t cnt = 0;
+    iterate_ll(head, count, &cnt);
+
+    printf("%lu\n", cnt);
+
+    deallocate_ll(head);
+}
+
+void deallocate_ll(stone_t *leaf) {
+    if (leaf == NULL) {
+        return;
+    }
+    stone_t* next = leaf->next;
+    free(leaf);
+    deallocate_ll(next);
+}
+
+void iterate_ll(stone_t *leaf, void (*cb)(stone_t*, void*), void* ctx) {
+    if (leaf == NULL) {
+        return;
+    }
+
+    cb(leaf, ctx);
+    iterate_ll(leaf->next, cb, ctx);
+}
+
+void blink(stone_t *leaf, void* ctx) {
+    if (leaf->value == 0) {
+        leaf->value = 1;
+    } else {
+        // Split in two
+        char buf[64];
+        sprintf(buf, "%lu", leaf->value);
+        size_t len = strlen(buf);
+        if (len % 2 == 0) {
+            char left[32];
+            memcpy(left, buf, len / 2);
+            left[len / 2] = '\0';
+            char right[32];
+            memcpy(right, buf + len / 2, len / 2);
+            right[len / 2] = '\0';
+            stone_t *left_stone = calloc(1, sizeof(left_stone[0]));
+            sscanf(left, "%lu", &left_stone->value);
+            sscanf(right, "%lu", &leaf->value);
+            if (leaf->prev) {
+                left_stone->prev = leaf->prev;
+                leaf->prev->next = left_stone;
+            }
+            leaf->prev = left_stone;
+            left_stone->next = leaf;
+        } else {
+            leaf->value *= 2024;
+        }
+    }
+}
+
+void count(stone_t *leaf, void* ctx) {
+    (*(uint64_t*)ctx)++;
+}
diff --git a/day11/input.txt b/day11/input.txt
new file mode 100644
index 0000000..bbc2705
--- /dev/null
+++ b/day11/input.txt
@@ -0,0 +1 @@
+112 1110 163902 0 7656027 83039 9 74
diff --git a/day11/sample.txt b/day11/sample.txt
new file mode 100644
index 0000000..9b26c84
--- /dev/null
+++ b/day11/sample.txt
@@ -0,0 +1 @@
+125 17