2024-03-07

tgyuuAn/DFS/스도쿠.py

@@ -0,0 +1,78 @@
+import sys
+
+def input(): return sys.stdin.readline().rstrip()
+
+board = []
+
+for _ in range(9): board.append(list(input()))
+
+def dfs(board, now_row, now_col):
+
+    # 이미 들어있는 칸일 경우
+    if board[now_row][now_col] != "0":
+        new_row = now_row
+        new_col = now_col + 1
+
+        if new_col >= 9:
+            new_col = 0
+            new_row += 1
+
+        # 스도쿠 완성
+        if new_row >= 9: return board
+
+        temp = dfs(board, new_row, new_col)
+
+        if temp is not None: return temp
+
+    # 비어있는 칸일 경우
+    else:
+        need_number = { str(x) for x in range(1,10) }
+
+        # 가로 행 검사 
+        for col in range(9):
+            if board[now_row][col] != "0":
+                need_number.discard(board[now_row][col])
+
+        # 세로 행 검사
+        for row in range(9):
+            if board[row][now_col] != "0":
+                need_number.discard(board[row][now_col])
+
+        # 3X3 검사
+        temp_row = (now_row//3)*3
+        temp_col = (now_col//3)*3
+        for inner_row in range(temp_row, temp_row+3):
+            for inner_col in range(temp_col, temp_col+3):
+                if board[inner_row][inner_col] != "0":
+                    need_number.discard(board[inner_row][inner_col])
+
+        # 만약 넣을 수 있는것이 없으면 None을 리턴   
+        if len(need_number) == 0: return None
+
+        need_number = sorted(list(map(int,need_number)))
+
+        for dedicate_number in need_number:
+            board[now_row][now_col] = str(dedicate_number)
+
+            new_row = now_row
+            new_col = now_col + 1
+
+            if new_col >= 9:
+                new_col = 0
+                new_row += 1
+
+            # 스도쿠 완성
+            if new_row >= 9: return board     
+
+            temp = dfs(board, new_row, new_col)
+
+            if temp is not None: return temp
+
+            board[now_row][now_col] = "0"
+
+    return None
+
+answer = dfs(board, 0, 0)
+
+for row in answer:
+    print("".join(row))

tgyuuAn/README.md

@@ -42,4 +42,5 @@
 | 38차시 | 2023.02.15 |  DP  | <a href="https://www.acmicpc.net/problem/2749">피보나치 수 3</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/137
 | 39차시 | 2023.02.18 |  DP  | <a href="https://www.acmicpc.net/problem/7579">앱</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/139
 | 40차시 | 2023.02.21 |  DP  | <a href="https://www.acmicpc.net/problem/31413">입대</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/142
+| 42차시 | 2023.03.07 |  DFS  | <a href="https://www.acmicpc.net/problem/2239">스도쿠</a> | https://github.com/AlgoLeadMe/AlgoLeadMe-1/pull/152
 ---