Add peoblem 46 .

1 files changed, 34 insertions, 0 deletions

diff --git a/cpp/46.cpp b/cpp/46.cpp
new file mode 100644
index 0000000..bfb3c83
--- /dev/null
+++ b/cpp/46.cpp
@@ -0,0 +1,34 @@
+#include <vector>
+
+using std::vector;
+
+class Solution {
+public:
+  void dfs(const vector<int> &nums, vector<int> &current, bool *num_used,
+           vector<vector<int>> &result) {
+    if (current.size() == nums.size()) {
+      result.push_back(current);
+      return;
+    }
+
+    for (int i = 0; i < nums.size(); i++) {
+      if (!num_used[i]) {
+        num_used[i] = true;
+        current.push_back(nums[i]);
+        dfs(nums, current, num_used, result);
+        current.pop_back();
+        num_used[i] = false;
+      }
+    }
+  }
+
+  vector<vector<int>> permute(vector<int> &nums) {
+    vector<int> current;
+    vector<vector<int>> result;
+    bool *num_used = new bool[nums.size()]{false};
+    dfs(nums, current, num_used, result);
+    delete[] num_used;
+
+    return result;
+  }
+};