From eb9f6ce83c8f5db1844c64df96f81ab91ec2c072 Mon Sep 17 00:00:00 2001
From: shinheekim <dev.shinheekim@gmail.com>
Date: Wed, 23 Jul 2025 13:39:03 +0900
Subject: [PATCH 1/3] contains-duplicate solution

---
 .gitignore                         |  1 +
 contains-duplicate/shinheekim.java | 15 +++++++++++++++
 2 files changed, 16 insertions(+)
 create mode 100644 contains-duplicate/shinheekim.java

diff --git a/.gitignore b/.gitignore
index d2a36c905..4de78d3f4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 .vscode/
 .DS_Store
 .env
+/leetcode-study.iml
diff --git a/contains-duplicate/shinheekim.java b/contains-duplicate/shinheekim.java
new file mode 100644
index 000000000..500e67260
--- /dev/null
+++ b/contains-duplicate/shinheekim.java
@@ -0,0 +1,15 @@
+import java.util.HashSet;
+import java.util.Set;
+
+class Solution {
+    public boolean containsDuplicate(int[] nums) {
+        Set<Integer> visited = new HashSet<>();
+
+        for (int n : nums){
+            if (!visited.add(n)){
+                return true;
+            }
+        }
+        return false; // 모든 값이 고유할 때
+    }
+}

From 9cd189bcdff8660dcafe64c52821fda2de8302a2 Mon Sep 17 00:00:00 2001
From: shinheekim <dev.shinheekim@gmail.com>
Date: Thu, 24 Jul 2025 10:50:48 +0900
Subject: [PATCH 2/3] two-sum solution

---
 two-sum/shinheekim.java | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 two-sum/shinheekim.java

diff --git a/two-sum/shinheekim.java b/two-sum/shinheekim.java
new file mode 100644
index 000000000..fc37d6fb6
--- /dev/null
+++ b/two-sum/shinheekim.java
@@ -0,0 +1,16 @@
+class Solution {
+    public int[] twoSum(int[] nums, int target) {
+        int[] result = new int[2];
+
+        for (int i = 0; i < nums.length; i++){
+            for (int j = i + 1; j < nums.length; j++){
+                if (nums[i] + nums[j] == target){
+                    result[0] = i;
+                    result[1] = j;
+                    return result;
+                }
+            }
+        }
+        return null;
+    }
+}

From 59119e5d64c9b9dd78859149f08bc5facaf666ee Mon Sep 17 00:00:00 2001
From: shinheekim <dev.shinheekim@gmail.com>
Date: Thu, 24 Jul 2025 11:12:29 +0900
Subject: [PATCH 3/3] =?UTF-8?q?gitignore=20=ED=8C=8C=EC=9D=BC=20=EB=B3=80?=
 =?UTF-8?q?=EA=B2=BD=20=EC=B7=A8=EC=86=8C?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .gitignore | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.gitignore b/.gitignore
index 4de78d3f4..d2a36c905 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,3 @@
 .vscode/
 .DS_Store
 .env
-/leetcode-study.iml