feat: add rust solution to lc problem: No.0046

solution/0000-0099/0046.Permutations/README.md

@@ -315,6 +315,40 @@ impl Solution {
 }
 ```
 
+```rust
+impl Solution {
+    #[allow(dead_code)]
+    pub fn permute(nums: Vec<i32>) -> Vec<Vec<i32>> {
+        let mut ret = Vec::new();
+        let mut cur_vec = Vec::new();
+        let mut vis = vec![false; nums.len() + 1];
+        Self::dfs(&nums, &mut vis, 0, &mut cur_vec, &mut ret);
+        ret
+    }
+
+    #[allow(dead_code)]
+    fn dfs(nums: &Vec<i32>, vis: &mut Vec<bool>, index: i32, cur_vec: &mut Vec<i32>, ans: &mut Vec<Vec<i32>>) {
+        let n = nums.len();
+        if index as usize == n {
+            ans.push(cur_vec.clone());
+            return;
+        }
+        // Otherwise, let's iterate the nums vector
+        for i in 0..n {
+            if !vis[i] {
+                // If this number hasn't been visited, then visit it
+                vis[i] = true;
+                cur_vec.push(nums[i]);
+                Self::dfs(nums, vis, index + 1, cur_vec, ans);
+                // Reset the changes
+                cur_vec.pop().unwrap();
+                vis[i] = false;
+            }
+        }
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0000-0099/0046.Permutations/README_EN.md

@@ -286,6 +286,40 @@ impl Solution {
 }
 ```
 
+```rust
+impl Solution {
+    #[allow(dead_code)]
+    pub fn permute(nums: Vec<i32>) -> Vec<Vec<i32>> {
+        let mut ret = Vec::new();
+        let mut cur_vec = Vec::new();
+        let mut vis = vec![false; nums.len() + 1];
+        Self::dfs(&nums, &mut vis, 0, &mut cur_vec, &mut ret);
+        ret
+    }
+
+    #[allow(dead_code)]
+    fn dfs(nums: &Vec<i32>, vis: &mut Vec<bool>, index: i32, cur_vec: &mut Vec<i32>, ans: &mut Vec<Vec<i32>>) {
+        let n = nums.len();
+        if index as usize == n {
+            ans.push(cur_vec.clone());
+            return;
+        }
+        // Otherwise, let's iterate the nums vector
+        for i in 0..n {
+            if !vis[i] {
+                // If this number hasn't been visited, then visit it
+                vis[i] = true;
+                cur_vec.push(nums[i]);
+                Self::dfs(nums, vis, index + 1, cur_vec, ans);
+                // Reset the changes
+                cur_vec.pop().unwrap();
+                vis[i] = false;
+            }
+        }
+    }
+}
+```
+
 ### **...**
 
 ```