Merge pull request #1834 from AlgorithmWithGod/zinnnn37

[20260125] BOJ / G4 / 좋다 / 김민진

Author: ShinHeeEul

zinnnn37/202601/25 BOJ G4 좋다.md

@@ -0,0 +1,71 @@
+```java
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Arrays;
+import java.util.StringTokenizer;
+
+public class BJ_1253_좋다 {
+
+    private static final BufferedReader  br = new BufferedReader(new InputStreamReader(System.in));
+    private static       StringTokenizer st;
+
+    private static int N, cnt;
+    private static long[] arr;
+
+    public static void main(String[] args) throws IOException {
+        init();
+        sol();
+    }
+
+    private static void init() throws IOException {
+        N = Integer.parseInt(br.readLine());
+        cnt = 0;
+
+        arr = new long[N];
+        st = new StringTokenizer(br.readLine());
+        for (int i = 0; i < N; i++) {
+            arr[i] = Long.parseLong(st.nextToken());
+        }
+        Arrays.sort(arr);
+    }
+
+    private static void sol() {
+        for (int i = 0; i < N; i++) {
+            if (isGood(i)) {
+                cnt++;
+            }
+        }
+        System.out.println(cnt);
+    }
+
+    private static boolean isGood(int idx) {
+        long target = arr[idx];
+        int  left   = 0;
+        int  right  = N - 1;
+
+        while (left < right) {
+            if (left == idx) {
+                left++;
+                continue;
+            } else if (right == idx) {
+                right--;
+                continue;
+            }
+
+            long current = arr[left] + arr[right];
+
+            if (current == target) {
+                return true;
+            } else if (current < target) {
+                left++;
+            } else {
+                right--;
+            }
+        }
+
+        return false;
+    }
+
+}
+```