[20250825] BOJ / G5 / 좋다 / 이종환

0224LJH/202508/25 BOJ 좋다.md

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+```java
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.StringTokenizer;
+
+
+public class Main {
+
+	static int numCnt,ans;
+	static int[] arr;
+	static HashMap<Integer,HashSet<Integer>> good;
+
+	public static void main(String[] args) throws IOException {
+		init();
+		process();
+		print();
+	}
+
+	public static void init() throws IOException {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		good = new HashMap<>();
+
+		numCnt = Integer.parseInt(br.readLine());
+		arr =new int[numCnt];
+		ans = 0;
+
+		StringTokenizer st = new StringTokenizer(br.readLine());
+		for (int i = 0; i < numCnt; i++) {
+			arr[i] = Integer.parseInt(st.nextToken());
+		}
+	}
+
+	public static void process() throws IOException {
+		for (int i = 0; i <numCnt; i++) {
+			if (good.containsKey(arr[i])) {
+				good.get(arr[i]).add(i);
+			} else {
+				good.put(arr[i], new HashSet<>());
+				good.get(arr[i]).add(i);
+			}
+		}
+
+
+		for (int i = 0; i < numCnt; i++) {
+			for (int j = i+1; j < numCnt; j++){
+				int sum = arr[i] + arr[j];
+
+				if (!good.containsKey(sum)) continue;
+
+				HashSet<Integer> idx = good.get(sum);
+
+				boolean isRemovable = false;
+
+				for (int n: idx) {
+					if (n != i && n != j) {
+						isRemovable = true;
+						break;
+					}
+				}
+
+				if (isRemovable) good.remove(sum);
+
+			}
+		}
+
+		int zeroCnt = 0;
+		for (int i = 0; i < numCnt; i++) if(arr[i] == 0) zeroCnt++;
+		if (zeroCnt >= 3) good.remove(0);
+
+		for (int i = 0; i < numCnt; i++) {
+			if (!good.containsKey(arr[i])) ans++;
+		}
+
+	}
+
+
+
+	public static void print() {
+		System.out.println(ans);
+	}
+}
+
+```