'commit'

TangDou/AcWing/Dfs/843.cpp

@@ -0,0 +1,37 @@
+#include <bits/stdc++.h>
+using namespace std;
+const int N = 20;
+int path[N];
+int n;
+int b1[N], b2[N], b3[N];
+
+void dfs(int u) {
+    if (u == n + 1) { // 全部行都摆上皇后
+        for (int i = 1; i <= n; i++) {
+            for (int j = 1; j <= n; j++) {
+                if (j == path[i])
+                    printf("Q");
+                else
+                    printf(".");
+            }
+            puts("");
+        }
+        puts("");
+        return;
+    }
+
+    for (int i = 1; i <= n; i++) { // x行y列
+        if (!b1[i] && !b2[u + i] && !b3[u - i + 8]) {
+            path[u] = i;
+            b1[i] = b2[u + i] = b3[u - i + 8] = 1;
+            dfs(u + 1);
+            b1[i] = b2[u + i] = b3[u - i + 8] = 0;
+        }
+    }
+}
+
+int main() {
+    cin >> n;
+    dfs(1);
+    return 0;
+}