[20250927] BOJ / G4 / 도서관 / 이종환

0224LJH/202509/27 BOJ 도서관.md

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+```java
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.*;
+
+class Main {
+
+	static int bookCnt, bookMax, plusMax, minusMax,ans;
+	static PriorityQueue<Integer> plusPq = new PriorityQueue<>(Collections.reverseOrder());
+	static PriorityQueue<Integer> minusPq = new PriorityQueue<>(Collections.reverseOrder());
+
+    public static void main(String[] args) throws NumberFormatException, IOException {
+       init();
+       process();
+       print();
+
+    }
+
+
+    public static void init() throws NumberFormatException, IOException {
+    	BufferedReader br= new BufferedReader(new InputStreamReader(System.in));
+    	StringTokenizer st = new StringTokenizer(br.readLine());
+
+    	bookCnt = Integer.parseInt(st.nextToken());
+    	bookMax = Integer.parseInt(st.nextToken());
+    	plusMax = 0;
+    	minusMax = 0;
+    	st = new StringTokenizer(br.readLine());
+
+    	for (int i = 0; i < bookCnt; i++) {
+    		int num = Integer.parseInt(st.nextToken());
+    		if (num < 0 ) {
+    			num *= -1;
+    			minusPq.add(num);
+    			minusMax = Math.max(minusMax, num);
+    		} else {
+    			plusPq.add(num);
+    			plusMax = Math.max(plusMax, num);
+    		}
+    	}
+
+    }
+
+    public static void process() throws IOException {   
+    	ans = 0;
+
+    	while (!minusPq.isEmpty()) {
+    		ans += minusPq.peek();
+    		for (int i = 0; i < bookMax; i++) {
+    			if (minusPq.isEmpty()) break;
+    			minusPq.poll();
+    		}
+
+    	}
+    	while (!plusPq.isEmpty()) {
+    		ans += plusPq.peek();
+    		for (int i = 0; i < bookMax; i++) {
+    			if (plusPq.isEmpty()) break;
+    			plusPq.poll();
+    		}
+
+    	}
+
+    	ans *= 2;
+    	ans -= Math.max(minusMax, plusMax);
+
+    }
+
+
+   public static void print() {
+      System.out.println(ans);
+    }
+}
+```