From 2de5c70ddba1cf672322ede4df4ee204de95f318 Mon Sep 17 00:00:00 2001
From: LiiNi-coder <97495437+LiiNi-coder@users.noreply.github.com>
Date: Sat, 4 Oct 2025 23:14:46 +0900
Subject: [PATCH] =?UTF-8?q?[20251004]=20BOJ=20/=20G4=20/=20List=20of=20Uni?=
 =?UTF-8?q?que=20Numbers=20/=20=EC=9D=B4=EC=9D=B8=ED=9D=AC?=
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---
 .../202510/04 BOJ List of Unique Numbers.md   | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 LiiNi-coder/202510/04 BOJ List of Unique Numbers.md

diff --git a/LiiNi-coder/202510/04 BOJ List of Unique Numbers.md b/LiiNi-coder/202510/04 BOJ List of Unique Numbers.md
new file mode 100644
index 00000000..10805af4
--- /dev/null
+++ b/LiiNi-coder/202510/04 BOJ List of Unique Numbers.md	
@@ -0,0 +1,33 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(                                                                                                                                                             new InputStreamReader(System.in));
+        int N = Integer.parseInt(br.readLine());
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        int[] arr = new int[N];
+        for(int i = 0; i < N; i++){
+            arr[i] = Integer.parseInt(st.nextToken());
+        }
+
+        long result = 0;
+        int l = 0;
+        int MAX = 100000;
+
+        int[] freq = new int[MAX + 1];
+        for(int r = 0; r < N; r++){
+            freq[arr[r]]++;
+            while(freq[arr[r]] > 1){
+                freq[arr[l]]--;
+                l++;
+            }
+            result += (r - l +1);
+        }
+
+        System.out.println(result);
+    }
+}
+
+```