修正0027.移除元素Rust語言版本

1. 根據題目須回傳i32而非&mut Vec<i32>
2. 改以Owner介紹的雙指針法解題

problems/0027.移除元素.md

@@ -201,19 +201,17 @@ end
 ```
 Rust:
 ```rust
-pub fn remove_element(nums: &mut Vec<i32>, val: i32) -> &mut Vec<i32> {
-    let mut start: usize = 0;
-    while start < nums.len() {
-        if nums[start] == val {
-            nums.remove(start);
+impl Solution {
+    pub fn remove_element(nums: &mut Vec<i32>, val: i32) -> i32 {
+        let mut slowIdx = 0;
+        for pos in (0..nums.len()) {
+            if nums[pos]!=val {
+                nums[slowIdx] = nums[pos];
+                slowIdx += 1;
+            }
         }
-        start += 1;
+        return (slowIdx) as i32;
     }
-    nums
-}
-fn main() {
-    let mut nums = vec![5,1,3,5,2,3,4,1];
-    println!("{:?}",remove_element(&mut nums, 5));
 }
 ```