1 files changed, 43 insertions, 0 deletions
diff --git a/experiments/fibonacci.c b/experiments/fibonacci.c
new file mode 100644
index 0000000..26fca0c
--- /dev/null
+++ b/experiments/fibonacci.c
@@ -0,0 +1,43 @@
+#include <stdint.h>
+
+/* Iterative Fibonacci. */
+uint32_t fib_iter(uint32_t n)
+{
+    uint32_t a = 0, b = 1;
+    for (uint32_t i = 0; i < n; i++) {
+        uint32_t t = a + b;
+        a = b;
+        b = t;
+    }
+    return a;
+}
+
+/* Naive recursive Fibonacci. */
+uint32_t fib_rec(uint32_t n)
+{
+    if (n < 2)
+        return n;
+    return fib_rec(n - 1) + fib_rec(n - 2);
+}
+
+/* Memoized Fibonacci (static table). */
+uint32_t fib_memo(uint32_t n)
+{
+    static uint32_t cache[48];
+    if (n < 2)
+        return n;
+    if (n >= sizeof(cache) / sizeof(cache[0]))
+        return fib_iter(n);
+    if (cache[n])
+        return cache[n];
+    return cache[n] = fib_memo(n - 1) + fib_memo(n - 2);
+}
+
+volatile uint32_t sink;
+
+int main(void)
+{
+    for (uint32_t n = 0; n < 20; n++)
+        sink = fib_iter(n) + fib_rec(n) + fib_memo(n);
+    return 0;
+}