From 727096b8e640f5d13e14f741df3995ad681ce613 Mon Sep 17 00:00:00 2001
From: Jeffrey Hsu <xfj12@outlook.com>
Date: Fri, 5 Dec 2025 21:18:40 +0800
Subject: [PATCH] 509

---
 include/solution/509.h | 14 ++++++++++++++
 src/509.c              | 14 ++++++++++++++
 tests/test_509.cpp     | 39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+)
 create mode 100644 include/solution/509.h
 create mode 100644 src/509.c
 create mode 100644 tests/test_509.cpp

diff --git a/include/solution/509.h b/include/solution/509.h
new file mode 100644
index 0000000..eed10ea
--- /dev/null
+++ b/include/solution/509.h
@@ -0,0 +1,14 @@
+// This file is generated by mkfile.py
+// Date: 2025-12-05
+
+#ifndef INC_509_H
+#define INC_509_H
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+    int fib(int n);
+#ifdef __cplusplus
+}
+#endif
+#endif // INC_509_H
diff --git a/src/509.c b/src/509.c
new file mode 100644
index 0000000..3d9e9d0
--- /dev/null
+++ b/src/509.c
@@ -0,0 +1,14 @@
+// This file is generated by mkfile.py
+// Date: 2025-12-05
+
+#include <solution/509.h>
+int fib(int n)
+{
+    int dp[n + 1];
+    dp[0] = 0;
+    if (n >= 1)
+        dp[1] = 1;
+    for (int i = 2; i <= n; i++)
+        dp[i] = dp[i - 1] + dp[i - 2];
+    return dp[n];
+}
\ No newline at end of file
diff --git a/tests/test_509.cpp b/tests/test_509.cpp
new file mode 100644
index 0000000..95a49ac
--- /dev/null
+++ b/tests/test_509.cpp
@@ -0,0 +1,39 @@
+// This file is generated by mkfile.py
+// Date: 2025-12-05
+
+#include <gtest/gtest.h>
+#include <solution/509.h>
+// Tests for fib (LeetCode 509)
+class FibTest : public ::testing::Test
+{
+  protected:
+    void AssertFib(int n, int expected)
+    {
+        ASSERT_EQ(fib(n), expected);
+    }
+};
+
+TEST_F(FibTest, Zero)
+{
+    AssertFib(0, 0);
+}
+
+TEST_F(FibTest, One)
+{
+    AssertFib(1, 1);
+}
+
+TEST_F(FibTest, Two)
+{
+    AssertFib(2, 1);
+}
+
+TEST_F(FibTest, Ten)
+{
+    AssertFib(10, 55);
+}
+
+TEST_F(FibTest, Twenty)
+{
+    AssertFib(20, 6765);
+}