Merge pull request #1534 from cezarbbb/Backtracking05

添加 0491.递增子序列 Rust版本

problems/0491.递增子序列.md

@@ -423,6 +423,57 @@ function findSubsequences(nums: number[]): number[][] {
 };
 ```
 
+### Rust
+**回溯+哈希**
+```Rust
+use std::collections::HashSet;
+impl Solution {
+    fn backtracking(result: &mut Vec<Vec<i32>>, path: &mut Vec<i32>, nums: &Vec<i32>, start_index: usize) {
+        if path.len() > 1 { result.push(path.clone()); }
+        let len = nums.len();
+        let mut uset: HashSet<i32> = HashSet::new();
+        for i in start_index..len {
+            if (!path.is_empty() && nums[i] < *path.last().unwrap()) || uset.contains(&nums[i]) { continue; }
+            uset.insert(nums[i]);
+            path.push(nums[i]);
+            Self::backtracking(result, path, nums, i + 1);
+            path.pop();
+        }
+    }
+
+    pub fn find_subsequences(nums: Vec<i32>) -> Vec<Vec<i32>> {
+        let mut result: Vec<Vec<i32>> = Vec::new();
+        let mut path: Vec<i32> = Vec::new();
+        Self::backtracking(&mut result, &mut path, &nums, 0);
+        result
+    }
+}
+```
+**回溯+数组**
+```Rust
+impl Solution {
+    fn backtracking(result: &mut Vec<Vec<i32>>, path: &mut Vec<i32>, nums: &Vec<i32>, start_index: usize) {
+        if path.len() > 1 { result.push(path.clone()); }
+        let len = nums.len();
+        let mut used = [0; 201];
+        for i in start_index..len {
+            if (!path.is_empty() && nums[i] < *path.last().unwrap()) || used[(nums[i] + 100) as usize] == 1 { continue; }
+            used[(nums[i] + 100) as usize] = 1;
+            path.push(nums[i]);
+            Self::backtracking(result, path, nums, i + 1);
+            path.pop();
+        }
+    }
+
+    pub fn find_subsequences(nums: Vec<i32>) -> Vec<Vec<i32>> {
+        let mut result: Vec<Vec<i32>> = Vec::new();
+        let mut path: Vec<i32> = Vec::new();
+        Self::backtracking(&mut result, &mut path, &nums, 0);
+        result
+    }
+}
+```
+
 ### C 
 
 ```c