Merge pull request #993 from AlgorithmWithGod/lkhyun

[20250928] BOJ / G4 / 좋다 / 이강현

Author: ShinHeeEul

lkhyun/202509/28 BOJ G4 좋다.md

@@ -0,0 +1,50 @@
+```java
+import java.util.*;
+import java.io.*;
+
+public class Main{
+    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    static StringTokenizer st;
+    static StringBuilder sb = new StringBuilder();
+    static int N;
+    static int[] arr;
+
+    public static void main(String[] args) throws Exception {
+        N = Integer.parseInt(br.readLine());
+        arr = new int[N];
+
+        st = new StringTokenizer(br.readLine());
+        for (int i = 0; i < N; i++) {
+            arr[i] = Integer.parseInt(st.nextToken());
+        }
+        Arrays.sort(arr);
+
+        int cnt = 0;
+        for (int i = 0; i < N; i++) {
+            int left = 0;
+            int right = N-1;
+            while(left < right){
+                if(left == i){
+                    left++;
+                    continue;
+                }
+                if(right == i){
+                    right--;
+                    continue;
+                }
+                if(arr[i] < arr[left] + arr[right]){
+                    right--;
+                }else if(arr[i] > arr[left] + arr[right]){
+                    left++;
+                }else{
+                    cnt++;
+                    break;
+                }
+            }   
+        }
+        bw.write(cnt+"");
+        bw.close();
+    }
+}
+```