Merge pull request #1270 from AlgorithmWithGod/0224LJH

[20251030] BOJ / G4 / 최대최소 / 이종환

Author: ShinHeeEul

0224LJH/202510/30 BOJ 최대최소.md

@@ -0,0 +1,159 @@
+```java
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.PriorityQueue;
+import java.util.StringTokenizer;
+
+public class Main {
+	
+	static BufferedReader br;
+	static StringTokenizer st;
+	static StringBuilder sb = new StringBuilder();
+	
+	static PriorityQueue<Integer> minQ = new PriorityQueue<>();
+	static PriorityQueue<Integer> maxQ = new PriorityQueue<>(Collections.reverseOrder());
+	
+	static HashMap<Integer,Integer> map = new HashMap<>();
+	
+	static int size,len,qCnt;
+	static int[][] arr,min,max;
+
+
+	
+    public static void main(String[] args) throws IOException {
+    	init();
+    	process();
+    	print();
+    }
+    
+    private static void init() throws IOException{
+    	br = new BufferedReader(new InputStreamReader(System.in));
+    	st = new StringTokenizer(br.readLine());
+    	size = Integer.parseInt(st.nextToken());
+    	len = Integer.parseInt(st.nextToken());
+    	qCnt = Integer.parseInt(st.nextToken());
+    	
+    	arr = new int[size][size];
+    	min = new int[size-len+1][size-len+1];
+    	max = new int[size-len+1][size-len+1];
+    	for (int i = 0; i < size; i++) {
+    		st = new StringTokenizer(br.readLine());
+    		for (int j = 0; j < size; j++) {
+    			arr[i][j] = Integer.parseInt(st.nextToken());
+    		}
+    	}
+    	
+    	
+    }
+    
+    private static void process() throws IOException {
+    	getBase();
+    	
+    	for (int i = 0; i < size-len+1; i++) {
+
+        	
+        	if (i != 0)goUp(i);
+        	PriorityQueue<Integer> preMinQ = new PriorityQueue<>();
+        	PriorityQueue<Integer> preMaxQ = new PriorityQueue<>(Collections.reverseOrder());
+        	HashMap<Integer,Integer> preMap = new HashMap<>();
+        	preMinQ.addAll(minQ);
+        	preMaxQ.addAll(maxQ);
+        	preMap.putAll(map);
+        	
+    		calculate(i,0);
+    		for (int j = 1; j < size-len+1; j++) {
+    			goRight(i,j);
+    			calculate(i,j);
+    		}
+    		
+    		minQ = preMinQ;
+    		maxQ = preMaxQ;
+    		map = preMap;
+    		
+    	}
+    	
+    	for (int i = 0; i < qCnt; i++) {
+    		st = new StringTokenizer(br.readLine());
+    		int y = Integer.parseInt(st.nextToken())-1;
+    		int x = Integer.parseInt(st.nextToken())-1;
+    		sb.append(max[y][x] - min[y][x]).append("\n");
+    	}
+    	
+
+    }
+    
+    private static void goUp(int y) {
+    	for (int i = 0; i < len; i++) {
+    		remove(y-1,i);
+    	}
+    	
+    	for (int i = 0; i < len; i++) {
+    		put(y+len-1,i);
+    	}
+    }
+    
+    private static void goRight(int y, int x) {
+    	for (int i = y; i < y+len; i++) {
+    		remove(i,x-1);
+    		put(i,x+len-1);
+    	}
+    }
+    
+
+	
+
+    private static void calculate(int y, int x) {
+    	int minNum = minQ.peek();
+    	int maxNum = maxQ.peek();
+    	while(map.get(minNum) == 0) {
+    		minQ.poll();
+    		minNum = minQ.peek();
+    	}
+    	while(map.get(maxNum) == 0) {
+    		maxQ.poll();
+    		maxNum = maxQ.peek();
+    	}
+    	min[y][x] = minNum;
+    	max[y][x] =maxNum;
+    	
+    }
+
+
+    
+    private static void getBase() {
+    	for (int i = 0; i < len; i++) {
+    		for (int j = 0; j < len; j++) {
+    			put(i,j);
+    		}
+    	}
+		
+	}
+    
+    private static void put(int y,int x) {
+    	int num  = arr[y][x];
+    	if (map.containsKey(num) && map.get(num) > 0) {
+    		map.replace(num, map.get(num)+1);
+    	} else {
+    		map.put(num, 1);
+    		minQ.add(num);
+    		maxQ.add(num);
+    	}
+    }
+    
+    private static void remove(int y,int x) {
+    	int num = arr[y][x];
+    	map.replace(num, map.get(num)-1);
+    }
+
+	private static void print() {
+    	System.out.print(sb);
+    }
+
+}
+```