From fc3c9ad297c45c1705967fd5fd95f713fb76d6f7 Mon Sep 17 00:00:00 2001
From: Zhao Zihe <zhkmxx930@163.com>
Date: Tue, 9 Oct 2018 21:55:48 +0800
Subject: [PATCH] Permutations CPP
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排列数，模板题
---
 solution/046.Permutations/Solution.cpp | 35 ++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 solution/046.Permutations/Solution.cpp

diff --git a/solution/046.Permutations/Solution.cpp b/solution/046.Permutations/Solution.cpp
new file mode 100644
index 0000000000000..53c6d493ec0e7
--- /dev/null
+++ b/solution/046.Permutations/Solution.cpp
@@ -0,0 +1,35 @@
+class Solution {
+public:
+	vector<vector<int>> permute(vector<int>& nums) {
+		if (nums.size() == 0) return{};
+		vector<vector<int>> res;
+		vector<int> curr_vec;
+		vector<bool> used;
+		for (int i = 0; i < nums.size(); i++)
+		{
+			used.push_back(false);
+		}
+		dfs(res, nums, 0, curr_vec, used);
+		return res;
+	}
+
+	void dfs(vector<vector<int>>& res, vector<int>& nums, int depth, vector<int> curr_vec, vector<bool> used)
+	{
+
+		if (depth >= nums.size())
+		{
+			res.emplace_back(curr_vec);
+			return;
+		}
+
+		for (int i = 0; i < nums.size(); i++)
+		{
+			if (used[i]) continue;
+			used[i] = true;
+			curr_vec.emplace_back(nums[i]);
+			dfs(res, nums, depth + 1, curr_vec, used);
+			curr_vec.pop_back();
+			used[i] = false;
+		}
+	}
+};