refact: 프렌즈4블록 문제 코드 개선

Author: Mingguriguri

minjeong/Simulation/2025-07-05-[PGS]-프렌즈4블록.py

@@ -1,45 +1,63 @@
-def check(m, n, board):
-    filter = [[0 for _ in range(n)] for _ in range(m)]
-    count = 0
-
-    for i in range(m - 1):
-        for j in range(n - 1):
-            a = board[i][j]
-            b = board[i][j + 1]
-            c = board[i + 1][j]
-            d = board[i + 1][j + 1]
-            if a == b == c == d and a != '0':
-                filter[i][j], filter[i][j + 1], filter[i + 1][j], filter[i + 1][j + 1] = 1, 1, 1, 1
-
+def check_remove(m, n, grid):
+    """
+    2×2 같은 블록을 찾아서, 지울 칸을 True로 표시한 2D 배열을 반환한다.
+    """
+    mark = [[False] * n for _ in range(m)]
+    for i in range(m-1):
+        for j in range(n-1):
+            current = grid[i][j]
+            if current and grid[i][j+1] == current \
+                and grid[i+1][j] == current \
+                and grid[i+1][j+1] == current:
+                mark[i][j] = mark[i][j+1] = mark[i+1][j] = mark[i+1][j+1] = True
+    return mark
+
+def remove_blocks(m, n, grid, mark):
+    """
+    mark 배열이 True인 칸으르 찾아서 빈칸으로 바꾸고,
+    삭제된 블록의 총 개수를 반환한다.
+    """
+    removed = 0
     for i in range(m):
         for j in range(n):
-            if filter[i][j] == 1:
-                count += 1
-                board[i][j] = '0'
-
-    if count == 0:
-        return 0
-
-    for i in range(m - 2, -1, -1):
-        for j in range(n):
-            k = i
-            while 0 <= k + 1 < m and board[k + 1][j] == '0':
-                k += 1
-            if k != i:
-                board[k][j] = board[i][j]
-                board[i][j] = '0'
-
-    return count
-
+            if mark[i][j]:
+                grid[i][j] = ""
+                removed += 1
+    return removed
+
+def down_blocks(m, n, grid):
+    """
+    중력을 적용하여, 각 열마다 빈칸 위의 블록을 아래로 당긴다.
+    """
+    for j in range(n):
+        stack = []
+        for i in range(m):
+            if grid[i][j] != "":
+                stack.append(grid[i][j])
+
+        for i in range(m-1, -1, -1):
+            if stack:
+                grid[i][j] = stack.pop()
+
+            else:
+                grid[i][j] = ""
 
 def solution(m, n, board):
-    answer = 0
-    board = list(map(list, board))
+    # 1. 입력 문자열을 2D 리스트로 변환
+    grid = [list(row) for row in board]
+    total_removed = 0
 
     while True:
-        temp = check(m, n, board)
-        if temp == 0:
+        # 2. 지울 칸 표시
+        mark = check_remove(m, n, grid)
+        # 3. 표시된 칸 삭제 및 개수 세기
+        removed = remove_blocks(m, n, grid, mark)
+        if removed == 0:
+            # 더이상 지울 블록이 없다면 반복 종료
             break
-        answer += temp
+        # 4. 전체 삭제 개수에 해당 칸의 삭제 개수 누적해서 더하기
+        total_removed += removed
+        # 5. 중력 적용
+        down_blocks(m, n, grid)
 
-    return answer
+    return total_removed