백준 2239번 스도쿠 v2

문제 링크: https://www.acmicpc.net/problem/2239

Author: skysign

백준 2239번 스도쿠 v2/main.py

@@ -0,0 +1,69 @@
+import sys
+
+
+def solve():
+    input = sys.stdin.readline
+    board = []
+    empties = []
+
+    for idx_row in range(9):
+        row = input().strip()
+        board.append([0 for _ in range(9)])
+        for idx_col in range(9):
+            board[idx_row][idx_col] = int(row[idx_col])
+
+            if board[idx_row][idx_col] == 0:
+                empties.append([idx_row, idx_col])
+
+    rec(board, 0, empties)
+
+    for idx_row in range(9):
+        print(''.join(list(map(str, board[idx_row]))))
+
+
+def rec(board, idx_empty, empties):
+    if len(empties) == idx_empty:
+        return True
+
+    idx_row, idx_col = empties[idx_empty]
+
+    for number in range(1, 10):
+        if False == can_place_row(board, idx_row, number):
+            continue
+
+        if False == can_place_col(board, idx_col, number):
+            continue
+
+        if False == can_place_3x3(board, idx_row, idx_col, number):
+            continue
+
+        board[idx_row][idx_col] = number
+        if rec(board, idx_empty + 1, empties):
+            return True
+        board[idx_row][idx_col] = 0
+
+    return False
+
+
+def can_place_row(board, idx_row, number) -> bool:
+    return number not in board[idx_row]
+
+
+def can_place_col(board, idx_col, number) -> bool:
+    return number not in [board[i][idx_col] for i in range(9)]
+
+
+def can_place_3x3(board, idx_row, idx_col, number) -> bool:
+    row = (idx_row // 3) * 3
+    col = (idx_col // 3) * 3
+
+    for i in range(row, row + 3):
+        for j in range(col, col + 3):
+            if board[i][j] == number:
+                return False
+
+    return True
+
+
+if __name__ == '__main__':
+    solve()

백준 2239번 스도쿠 v2/test1.txt

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+103000509
+002109400
+000704000
+300502006
+060000050
+700803004
+000401000
+009205800
+804000107

백준 2239번 스도쿠 v2/test1_answer.txt

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+143628579
+572139468
+986754231
+391542786
+468917352
+725863914
+237481695
+619275843
+854396127

백준 2239번 스도쿠 v2/test_main.py

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+import sys
+from pathlib import Path
+from unittest import TestCase
+from main import solve
+
+
+class Test(TestCase):
+    def my_solve(self, testcase_input):
+        sys.stdin = open(testcase_input, 'r')
+        stdout = sys.stdout
+        sys.stdout = open('stdout.txt', 'w')
+        solve()
+        sys.stdout.close()
+        sys.stdout = stdout
+
+    def test_solve(self, testcase_number: str):
+        self.my_solve('test' + testcase_number + '.txt')
+        self.assertEqual(
+            Path('test' + testcase_number + '_answer.txt').read_text().strip(),
+            Path('stdout.txt').read_text().strip())
+
+    def test1_solve(self):
+        self.test_solve('1')