6-froglike6

froglike6/README.md

@@ -7,4 +7,5 @@
  | 3차시 | 2025.03.24 |  정수  | [피보나치 수와 최대공약수](https://www.acmicpc.net/problem/11778)|https://github.com/AlgoLeadMe/AlgoLeadMe-13/pull/9|
  | 4차시 | 2025.03.30 | 그래프 | [친구](https://www.acmicpc.net/problem/1058)|https://github.com/AlgoLeadMe/AlgoLeadMe-13/pull/16|
  | 5차시 | 2025.04.01 |  정수  | [개구리](https://www.acmicpc.net/problem/25333)|https://github.com/AlgoLeadMe/AlgoLeadMe-13/pull/17|
+ | 6차시 | 2025.04.07 | 백트래킹| [N-Queen](https://www.acmicpc.net/problem/9663)|https://github.com/AlgoLeadMe/AlgoLeadMe-13/pull/24|
  ---

froglike6/backtracking/9663.py

@@ -0,0 +1,17 @@
+def dfs(row, cols, diag1, diag2):
+    global count
+    if row == n:
+        count += 1
+        return
+    available_positions = (~(cols | diag1 | diag2)) & ((1 << n) - 1)
+    while available_positions:
+        position = available_positions & -available_positions
+        available_positions &= available_positions - 1
+        dfs(row + 1,
+            cols | position,
+            (diag1 | position) << 1,
+            (diag2 | position) >> 1)
+n = int(input())
+count = 0
+dfs(0, 0, 0, 0)
+print(count)