Study/260307

problems/SWEA/p1767v2/Solution.java

@@ -0,0 +1,277 @@
+/*
+ * (1767) [SW Test 샘플문제] 프로세서 연결하기
+ * https://swexpertacademy.com/main/code/problem/problemDetail.do?contestProbId=AV4suNtaXFEDFAUf&categoryId=AV4suNtaXFEDFAUf&categoryType=CODE&problemTitle=1767&orderBy=FIRST_REG_DATETIME&selectCodeLang=ALL&select-1=&pageSize=10&pageIndex=1
+ */
+import java.io.*;
+import java.util.*;
+
+public class Solution {
+  static BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
+  static StringBuilder output = new StringBuilder();
+  static StringTokenizer input;
+
+  // ----------------------------------------------------------
+
+  public static void main(String[] args) throws IOException {
+    final int testCount =  nextInt();
+
+    for (int testCase = 1; testCase <= testCount; testCase++) {
+      new Solution(testCase).run();
+    }
+
+    System.out.print(output.toString());
+  }
+
+  // ----------------------------------------------------------
+
+  static final int[] DIR_X = { -1,  1,  0,  0 };
+  static final int[] DIR_Y = {  0,  0, -1,  1 };
+  static final int[] REVERSE = { 1, 0, 3, 2 };
+  static final int DIR_LEN = 4;
+
+  int testCase;
+  int answer;
+  int boardSize;
+  int[][] board;
+  List<Pos> coreList;
+  int coreLen;
+
+  public Solution(int testCase) { this.testCase = testCase; }
+  public void run() throws IOException { input(); solve(); print(); }
+
+  private void input() throws IOException {
+    coreList = new ArrayList<>();
+    boardSize = nextInt();
+    board = new int[boardSize][boardSize];
+
+    for (int y = 0; y < boardSize; y++) {
+      for (int x = 0; x < boardSize; x++) {
+        board[y][x] = nextInt();
+
+        if (board[y][x] == 1 &&
+            x != 0 && x != boardSize - 1 &&
+            y != 0 && y != boardSize - 1
+        ) {
+          coreList.add(new Pos(x, y));
+        }
+      }
+    }
+
+    coreLen = coreList.size();
+  }
+
+  private void solve() {
+    answer = dfs(0, 0, 0).len;
+  }
+
+  private Result dfs(int core, int cnt, int len) {
+    if (core == coreLen) return new Result(cnt, len);
+
+    Pos pos = coreList.get(core);
+
+    // 수정된 버전: 속도가 더 빠르다.
+    // 4방향 탐색 성공 여부와 관계 없이 무조건 해당 코어를 배제한 경우도 탐색해야 함
+    Result result = dfs(core + 1, cnt, len);  
+
+    for (int dir = 0; dir < DIR_LEN; dir++) {
+      int nx = pos.x + DIR_X[dir];
+      int ny = pos.y + DIR_Y[dir];
+
+      int current = 0;
+      while (isInsideBoard(nx, ny) && board[ny][nx] == 0) {
+        board[ny][nx] = 2;
+
+        current++;
+
+        nx += DIR_X[dir];
+        ny += DIR_Y[dir];
+      }
+
+      if (!isInsideBoard(nx, ny) && current != 0) {
+        result = Result.selectBest(result, dfs(core + 1, cnt + 1, len + current));
+      }
+
+      undoBoard(nx, ny, dir, current);
+    }
+
+    return result;
+  }
+
+  private void undoBoard(int x, int y, int dir, int len) {
+    int rdir = REVERSE[dir];
+
+    for (int cnt = 0; cnt < len; cnt++) {
+      x += DIR_X[rdir];
+      y += DIR_Y[rdir];
+
+      board[y][x] = 0;
+    }
+  }
+
+  private boolean isInsideBoard(int x, int y) {
+    return x >= 0 && x < boardSize && y >= 0 && y < boardSize;
+  }
+
+  private void print() {
+    output
+      .append('#')
+      .append(testCase)
+      .append(' ')
+      .append(answer)
+      .append('\n');
+  }
+
+  // ----------------------------------------------------------
+
+  static class Pos {
+    int x, y;
+
+    public Pos(int x, int y) {
+      this.x = x;
+      this.y = y;
+    }
+  }
+
+  // ----------------------------------------------------------
+
+  static class Result {
+    int cnt, len;
+
+    public Result(int cnt, int len) {
+      this.cnt = cnt;
+      this.len = len;
+    }
+
+    public Result() {
+      this(0, Integer.MAX_VALUE);
+    }
+
+    public static Result selectBest(Result a, Result b) {
+      if (a.cnt == b.cnt) {
+        if (a.len < b.len) {
+          return a;
+        } else {
+          return b;
+        }
+      } else if (a.cnt > b.cnt) {
+        return a;
+      } else {
+        return b;
+      }
+    }
+  }
+
+  // ----------------------------------------------------------
+
+  static String next() throws IOException {
+    if (input == null || !input.hasMoreTokens())
+      input = new StringTokenizer(reader.readLine().trim());
+    return input.nextToken();
+  }
+
+  static int nextInt() throws IOException {
+    return Integer.parseInt(next());
+  }
+}
+
+
+
+
+
+/*
+
+[예시 입력]
+9
+7
+0 0 1 0 0 0 0
+0 0 1 0 0 0 0
+0 0 0 0 0 1 0
+0 0 0 0 0 0 0
+1 1 0 1 0 0 0
+0 1 0 0 0 0 0
+0 0 0 0 0 0 0
+9
+0 0 0 0 0 0 0 0 0
+0 0 1 0 0 0 0 0 1
+1 0 0 0 0 0 0 0 0
+0 0 0 1 0 0 0 0 0
+0 1 0 0 0 0 0 0 0
+0 0 0 0 0 0 1 0 0
+0 0 0 1 0 0 0 0 0
+0 0 0 0 0 0 0 1 0
+0 0 0 0 0 0 0 0 1
+11
+0 0 1 0 0 0 0 0 0 0 0
+0 0 0 0 0 0 0 0 0 0 0
+0 0 0 0 0 0 0 0 0 0 1
+0 0 0 1 0 0 0 0 1 0 0
+0 1 0 1 1 0 0 0 1 0 0
+0 0 0 0 0 0 0 0 0 0 0
+0 0 0 0 0 0 0 1 0 0 0
+0 0 0 0 0 0 0 0 0 0 0
+0 0 0 0 0 0 0 0 1 0 0
+0 0 0 0 0 0 1 0 0 0 0
+0 0 0 0 0 0 0 0 0 0 0
+7
+1 1 1 1 1 1 1
+1 0 0 1 0 0 1
+1 0 0 0 0 0 1
+1 1 0 0 0 0 0
+1 0 0 0 0 0 1
+0 0 0 0 0 1 1
+1 1 1 0 1 1 1
+9
+0 0 0 1 0 1 1 1 0
+1 0 0 1 0 0 0 0 0
+1 0 0 1 0 0 0 0 0
+1 0 0 0 0 0 1 1 1
+0 0 0 0 1 0 0 0 0
+1 1 1 0 0 0 0 0 1
+0 0 0 0 0 1 0 0 1
+0 0 0 0 0 1 0 0 1
+0 1 1 1 0 1 0 0 0
+5
+0 0 0 0 0
+0 0 1 0 0
+0 1 1 1 0
+0 0 1 0 0
+0 0 0 0 0
+7
+1 1 1 1 1 1 1
+1 0 0 1 0 0 1
+1 0 0 0 0 0 1
+1 1 0 0 0 0 1
+1 0 0 0 0 0 1
+1 0 0 0 0 1 1
+1 1 1 1 1 1 1
+7
+0 0 0 0 0 0 0
+0 0 0 0 0 0 0
+0 0 0 0 0 0 0
+0 0 0 1 0 0 0
+0 0 0 0 0 0 0
+0 0 0 0 0 0 0
+0 0 0 0 0 0 0
+7
+0 0 0 0 0 0 0
+0 0 0 0 0 0 0
+0 0 0 0 0 0 0
+0 0 1 1 0 0 0
+0 0 0 0 0 0 0
+0 0 0 0 0 0 0
+0 0 0 0 0 0 0
+
+
+[예시 출력]
+#1 12
+#2 10
+#3 24
+#4 10
+#5 40
+#6 4
+#7 0
+#8 3
+#9 5
+
+
+ */