[20251119] BOJ / G5 / 상어 초등학교 / 이준희

Author: JHLEE325

JHLEE325/202511/19 BOJ G5 상어초등학교.md

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+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    static int N;
+    static int[][] classroom;
+    static int[][] likes;
+    static int[] dr = {-1, 1, 0, 0};
+    static int[] dc = {0, 0, -1, 1};
+
+    public static void main(String[] args) throws Exception {
+
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        N = Integer.parseInt(br.readLine());
+
+        classroom = new int[N][N];
+        likes = new int[N*N + 1][4];
+
+        List<Integer> order = new ArrayList<>();
+
+        for (int i = 0; i < N * N; i++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            int student = Integer.parseInt(st.nextToken());
+            order.add(student);
+
+            for (int j = 0; j < 4; j++) {
+                likes[student][j] = Integer.parseInt(st.nextToken());
+            }
+        }
+
+        for (int student : order) {
+            placeStudent(student);
+        }
+
+        System.out.println(calculateScore());
+    }
+
+    static void placeStudent(int student) {
+
+        int bestR = -1, bestC = -1;
+        int bestLike = -1;
+        int bestEmpty = -1;
+
+        for (int r = 0; r < N; r++) {
+            for (int c = 0; c < N; c++) {
+
+                if (classroom[r][c] != 0) continue;
+
+                int likeCnt = 0;
+                int emptyCnt = 0;
+
+                for (int d = 0; d < 4; d++) {
+                    int nr = r + dr[d];
+                    int nc = c + dc[d];
+
+                    if (nr < 0 || nc < 0 || nr >= N || nc >= N) continue;
+
+                    if (classroom[nr][nc] == 0) emptyCnt++;
+                    else {
+                        int other = classroom[nr][nc];
+                        if (isLike(student, other)) likeCnt++;
+                    }
+                }
+
+                if (likeCnt > bestLike ||
+                        (likeCnt == bestLike && emptyCnt > bestEmpty) ||
+                        (likeCnt == bestLike && emptyCnt == bestEmpty && r < bestR) ||
+                        (likeCnt == bestLike && emptyCnt == bestEmpty && r == bestR && c < bestC)) {
+
+                    bestR = r;
+                    bestC = c;
+                    bestLike = likeCnt;
+                    bestEmpty = emptyCnt;
+                }
+            }
+        }
+
+        classroom[bestR][bestC] = student;
+    }
+
+    static boolean isLike(int student, int other) {
+        for (int x : likes[student]) {
+            if (x == other) return true;
+        }
+        return false;
+    }
+
+    static int calculateScore() {
+        int score = 0;
+
+        for (int r = 0; r < N; r++) {
+            for (int c = 0; c < N; c++) {
+
+                int student = classroom[r][c];
+                int likeCnt = 0;
+
+                for (int d = 0; d < 4; d++) {
+                    int nr = r + dr[d];
+                    int nc = c + dc[d];
+
+                    if (nr < 0 || nc < 0 || nr >= N || nc >= N) continue;
+
+                    int other = classroom[nr][nc];
+                    if (isLike(student, other)) likeCnt++;
+                }
+
+                if (likeCnt > 0) {
+                    score += (int) Math.pow(10, likeCnt - 1);
+                }
+            }
+        }
+
+        return score;
+    }
+}
+```