diff --git a/include/solution/387.h b/include/solution/387.h
new file mode 100644
index 0000000..d34d863
--- /dev/null
+++ b/include/solution/387.h
@@ -0,0 +1,11 @@
+#ifndef INC_387_H
+#define INC_387_H
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+    int firstUniqChar(char *s);
+#ifdef __cplusplus
+}
+#endif
+#endif
diff --git a/src/387.c b/src/387.c
new file mode 100644
index 0000000..da51b7c
--- /dev/null
+++ b/src/387.c
@@ -0,0 +1,17 @@
+#include <solution/387.h>
+#include <string.h>
+
+int firstUniqChar(char *s)
+{
+    int hash[26];
+    memset(hash, 0, sizeof(int) * 26);
+
+    for (int idx = 0; s[idx]; idx++)
+        hash[s[idx] - 'a']++;
+
+    for (int idx = 0; s[idx]; idx++)
+        if (hash[s[idx] - 'a'] == 1)
+            return idx;
+
+    return -1;
+}
\ No newline at end of file
diff --git a/tests/test_387.cpp b/tests/test_387.cpp
new file mode 100644
index 0000000..480ac81
--- /dev/null
+++ b/tests/test_387.cpp
@@ -0,0 +1,51 @@
+#include <gtest/gtest.h>
+#include <solution/387.h>
+
+class FirstUniqCharTest : public ::testing::Test
+{
+  protected:
+    void AssertFirstUniqChar(const std::string &input, int expected)
+    {
+        char buf[1001];
+        strncpy(buf, input.c_str(), sizeof(buf));
+        buf[1000] = '\0'; // 防止越界
+        int result = firstUniqChar(buf);
+        EXPECT_EQ(result, expected);
+    }
+};
+
+// 示例 1：leetcode → 'l' 是第一个唯一字符，索引 0
+TEST_F(FirstUniqCharTest, Example1)
+{
+    AssertFirstUniqChar("leetcode", 0);
+}
+
+// 示例 2：loveleetcode → 'v' 是第一个唯一字符，索引 2
+TEST_F(FirstUniqCharTest, Example2)
+{
+    AssertFirstUniqChar("loveleetcode", 2);
+}
+
+// 示例 3：aabb → 没有唯一字符，返回 -1
+TEST_F(FirstUniqCharTest, Example3)
+{
+    AssertFirstUniqChar("aabb", -1);
+}
+
+// 边界测试：空字符串
+TEST_F(FirstUniqCharTest, EmptyString)
+{
+    AssertFirstUniqChar("", -1);
+}
+
+// 边界测试：单字符
+TEST_F(FirstUniqCharTest, SingleChar)
+{
+    AssertFirstUniqChar("z", 0);
+}
+
+// 更多测试：末尾唯一字符
+TEST_F(FirstUniqCharTest, UniqueAtEnd)
+{
+    AssertFirstUniqChar("aabbc", 4); // 'c' 是唯一字符
+}
\ No newline at end of file