From 73c77e96454a9a0ac9b3a794286187cbe4734cfe Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Borba?= <andre.borbaaf2b@gmail.com>
Date: Sat, 19 Sep 2026 09:26:36 -0300
Subject: [PATCH] =?UTF-8?q?=F0=9F=9F=A2=20Port=20problem=20387=20(First=20?=
 =?UTF-8?q?Unique=20Character=20in=20a=20String)=20from=20Swift=20to=20C++?=
 =?UTF-8?q?23?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Replaces swift/387.swift with
solutions/0301-0400/0387-first-unique-character-in-a-string/, using a
fixed 26-slot count array instead of a hash map.
---
 .../README.md                                 | 11 +++++++++
 .../solution.cpp                              | 23 +++++++++++++++++++
 .../solution.hpp                              | 11 +++++++++
 .../test.cpp                                  |  9 ++++++++
 swift/387.swift                               | 17 --------------
 5 files changed, 54 insertions(+), 17 deletions(-)
 create mode 100644 solutions/0301-0400/0387-first-unique-character-in-a-string/README.md
 create mode 100644 solutions/0301-0400/0387-first-unique-character-in-a-string/solution.cpp
 create mode 100644 solutions/0301-0400/0387-first-unique-character-in-a-string/solution.hpp
 create mode 100644 solutions/0301-0400/0387-first-unique-character-in-a-string/test.cpp
 delete mode 100644 swift/387.swift

diff --git a/solutions/0301-0400/0387-first-unique-character-in-a-string/README.md b/solutions/0301-0400/0387-first-unique-character-in-a-string/README.md
new file mode 100644
index 0000000..21ed255
--- /dev/null
+++ b/solutions/0301-0400/0387-first-unique-character-in-a-string/README.md
@@ -0,0 +1,11 @@
+# 387. First Unique Character in a String
+
+[LeetCode problem 387](https://leetcode.com/problems/first-unique-character-in-a-string/)
+
+- **Difficulty**: Easy
+- **Tags**: hash-table, string, queue, counting
+
+## Description
+
+Given a string `s`, return the index of the first non-repeating character,
+or `-1` if none exists.
diff --git a/solutions/0301-0400/0387-first-unique-character-in-a-string/solution.cpp b/solutions/0301-0400/0387-first-unique-character-in-a-string/solution.cpp
new file mode 100644
index 0000000..237198e
--- /dev/null
+++ b/solutions/0301-0400/0387-first-unique-character-in-a-string/solution.cpp
@@ -0,0 +1,23 @@
+#include "solution.hpp"
+
+#include <array>
+
+namespace leetcode::p0387 {
+
+int solve(const std::string& s) {
+    std::array<int, 26> counts{};
+
+    for (char c : s) {
+        ++counts.at(static_cast<std::size_t>(c - 'a'));
+    }
+
+    for (std::size_t i = 0; i < s.size(); ++i) {
+        if (counts.at(static_cast<std::size_t>(s[i] - 'a')) == 1) {
+            return static_cast<int>(i);
+        }
+    }
+
+    return -1;
+}
+
+} // namespace leetcode::p0387
diff --git a/solutions/0301-0400/0387-first-unique-character-in-a-string/solution.hpp b/solutions/0301-0400/0387-first-unique-character-in-a-string/solution.hpp
new file mode 100644
index 0000000..72d932c
--- /dev/null
+++ b/solutions/0301-0400/0387-first-unique-character-in-a-string/solution.hpp
@@ -0,0 +1,11 @@
+#pragma once
+
+#include <string>
+
+namespace leetcode::p0387 {
+
+// optimized: O(n) time, O(1) space — fixed 26-slot count array (assumes
+// lowercase English letters, per the problem's constraints), two passes.
+int solve(const std::string& s);
+
+} // namespace leetcode::p0387
diff --git a/solutions/0301-0400/0387-first-unique-character-in-a-string/test.cpp b/solutions/0301-0400/0387-first-unique-character-in-a-string/test.cpp
new file mode 100644
index 0000000..9c7096a
--- /dev/null
+++ b/solutions/0301-0400/0387-first-unique-character-in-a-string/test.cpp
@@ -0,0 +1,9 @@
+#include <catch2/catch_test_macros.hpp>
+
+#include "solution.hpp"
+
+TEST_CASE("Problem 387", "[p0387]") {
+    CHECK(leetcode::p0387::solve("leetcode") == 0);
+    CHECK(leetcode::p0387::solve("loveleetcode") == 2);
+    CHECK(leetcode::p0387::solve("aabb") == -1);
+}
diff --git a/swift/387.swift b/swift/387.swift
deleted file mode 100644
index 3f4dece..0000000
--- a/swift/387.swift
+++ /dev/null
@@ -1,17 +0,0 @@
-class Solution {
-    func firstUniqChar(_ s: String) -> Int {
-        var dict: [Character : Int] = [:]
-
-        for character in s {
-            dict[character, default: 0] += 1
-        }
-
-        for (i, v) in s.enumerated() {
-            if dict[v] == 1 {
-                return i
-            }
-        }
-
-        return -1
-    }
-}
\ No newline at end of file