Create 백준-1253-좋다.java

Author: rhkr8521

2025-08-14/곽태근/백준-1253-좋다.java

@@ -0,0 +1,54 @@
+
+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));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+        int N = Integer.parseInt(br.readLine());
+        int answer = 0;
+        long[] arr = new long[N];
+
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        for(int i = 0; i<N; i++){
+            arr[i] = Integer.parseInt(st.nextToken());
+        }
+
+        Arrays.sort(arr);
+
+        for(int k = 0; k<N; k++){
+
+            long find = arr[k];
+            int start = 0;
+            int end = N-1;
+
+            while(start < end){
+
+                if (arr[start] + arr[end] == find){
+
+                    if(start != k && end != k){
+                        answer++;
+                        break;
+                    }else if( start == k){
+                        start++;
+                    }else if( end == k){
+                        end--;
+                    }
+                } else if(arr[start] + arr[end] > find){
+                    end--;
+                }else if (arr[start] + arr[end] < find){
+                    start++;
+                }
+            }
+        }
+
+        bw.write(answer+"");
+        bw.flush();
+    }
+
+}