[백준 11559] Puyo Puyo - 시뮬레이션

Author: HiiWee

hoseok/week35/Boj11559.java

@@ -0,0 +1,161 @@
+import java.io.*;
+import java.util.*;
+
+class Main {
+
+    static class Node {
+        int r, c;
+
+        Node(int r, int c) {
+            this.r = r;
+            this.c = c;
+        }
+    }
+
+    private static final int[] rows = {-1, 0, 1, 0};
+    private static final int[] cols = {0, 1, 0, -1};
+
+    private static final char[][] map = new char[12][6];
+    private static final List<Node> bubbles = new ArrayList<>();
+
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+        for (int i = 0; i < 12; i++) {
+            String line = br.readLine();
+            for (int j = 0; j < 6; j++) {
+                map[i][j] = line.charAt(j);
+            }
+        }
+
+        int count = 0;
+        while (bubblePop()) {
+            count++;
+            moveDown();
+        }
+
+        bw.write(count + "");
+        bw.flush();
+        bw.close();
+    }
+
+    public static void moveDown() {
+        for (int i = 0; i < 6; i++) {
+            while (true) {
+                // 일단 해당 열의 마지막 행부터 차례로 .을 찾기
+                int firstDot = findFirstDot(i);
+                if (firstDot == -1) {
+                    break;
+                }
+                // . 이후에 심볼이 있다면 그 사이 공간은 터진 공간임
+                int firstSymbolIndex = findFirstSymbolAfter(i, firstDot);
+                if (firstSymbolIndex == -1) {
+                    break;
+                }
+                // 첫번째 심볼이후 끝나는 자리를 찾음
+                int secondSymbolIndex = findLastSymbolAfter(i, firstSymbolIndex);
+
+                // 찾은 심볼을 firstDot위치부터 채워넣음
+                moveBubbleDown(i, firstDot, firstSymbolIndex, secondSymbolIndex);
+            }
+        }
+    }
+
+    public static void moveBubbleDown(int col, int firstDot, int startInclusive, int endInclusive) {
+        for (int i = startInclusive; i >= endInclusive; i--) {
+            map[firstDot--][col] = map[i][col];
+            map[i][col] = '.';
+        }
+    }
+
+    public static int findLastSymbolAfter(int col, int index) {
+        for (int i = index; i >= 0; i--) {
+            if (map[i][col] == '.') {
+                return i + 1;
+            }
+        }
+        return 0;
+    }
+
+    public static int findFirstSymbolAfter(int col, int index) {
+        for (int i = index; i >= 0; i--) {
+            if (map[i][col] != '.') {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    public static int findFirstDot(int col) {
+        for (int i = 11; i >= 0; i--) {
+            if (map[i][col] == '.') {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    public static boolean bubblePop() {
+        boolean isPop = false;
+        boolean[][] visited = new boolean[12][6];
+
+        for (int i = 0; i < 12; i++) {
+            for (int j = 0; j < 6; j++) {
+                if (!visited[i][j] && map[i][j] != '.') {
+                    isPop |= bfs(visited, new Node(i, j));
+                }
+            }
+        }
+        if (isPop) {
+            removeBubbles();
+            bubbles.clear();
+        }
+        return isPop;
+    }
+
+    public static void removeBubbles() {
+        for (Node node : bubbles) {
+            map[node.r][node.c] = '.';
+        }
+    }
+
+    public static boolean bfs(boolean[][] visited, Node startNode) {
+        List<Node> tempNodes = new ArrayList<>();
+        Queue<Node> que = new LinkedList<>();
+
+        tempNodes.add(startNode);
+        que.offer(startNode);
+        visited[startNode.r][startNode.c] = true;
+        char targetSymbol = map[startNode.r][startNode.c];
+
+        while (!que.isEmpty()) {
+            Node curNode = que.poll();
+
+            for (int i = 0; i < 4; i++) {
+                int nextR = rows[i] + curNode.r;
+                int nextC = cols[i] + curNode.c;
+
+                if (checks(nextR, nextC)) {
+                    continue;
+                }
+
+                if (!visited[nextR][nextC] && map[nextR][nextC] == targetSymbol) {
+                    visited[nextR][nextC] = true;
+                    Node nextNode = new Node(nextR, nextC);
+                    tempNodes.add(nextNode);
+                    que.offer(nextNode);
+                }
+            }
+        }
+        if (tempNodes.size() >= 4) {
+            bubbles.addAll(tempNodes);
+            return true;
+        }
+        return false;
+    }
+
+    public static boolean checks(int r, int c) {
+        return r < 0 || r >= 12 || c < 0 || c >= 6;
+    }
+}