Add problem 526 .

1 files changed, 29 insertions, 0 deletions

diff --git a/cpp/526.cpp b/cpp/526.cpp
new file mode 100644
index 0000000..19f445f
--- /dev/null
+++ b/cpp/526.cpp
@@ -0,0 +1,29 @@
+#include <vector>
+
+using std::vector;
+
+class Solution {
+public:
+  void dfs(int N, int index, bool *num_used, int &result) {
+    if (index > N) {
+      result += 1;
+      return;
+    }
+
+    for (int num = 1; num <= N; num++) {
+      if (!num_used[num] && (num % index == 0 || index % num == 0)) {
+        num_used[num] = true;
+        dfs(N, index + 1, num_used, result);
+        num_used[num] = false;
+      }
+    }
+  }
+
+  int countArrangement(int N) {
+    bool *num_used = new bool[N + 1]{false};
+    int result = 0;
+    dfs(N, 1, num_used, result);
+    delete[] num_used;
+    return result;
+  }
+};