complete 9663_bt.py for pypy3

zeta_python/9663_bt.py

@@ -0,0 +1,39 @@
+import sys
+
+input = sys.stdin.readline
+print = sys.stdout.write
+
+N = int(input())
+
+
+def solve(N: int) -> int:
+    count = 0
+    D = []
+    for i in range(N):
+        T = [i]
+        D.append((1, T))
+
+    while D:
+        now, xs = D.pop()
+        if now == N:
+            count += 1
+            continue
+
+        for i in range(N):
+            if i in xs:
+                continue
+
+            flag = True
+            for j in range(now):
+                y = xs[j]
+                if abs(now - j) == abs(y - i):
+                    flag = False
+                    break
+            if flag:
+                D.append((now + 1, xs + [i]))
+
+    return count
+
+
+if __name__ == "__main__":
+    print(str(solve(N)))