feat: add rust solution to lc problem: No.0214 (doocs#1642)

No.0214.Shortest Palindrome

Author: poltao

solution/0200-0299/0214.Shortest Palindrome/README.md

@@ -161,6 +161,32 @@ func shortestPalindrome(s string) string {
 }
 ```
 
+### **Rust**
+
+```rust
+impl Solution {
+    pub fn shortest_palindrome(s: String) -> String {
+        let base = 131;
+        let (mut idx, mut prefix, mut suffix, mut mul) = (0, 0, 0, 1);
+        for (i, c) in s.chars().enumerate() {
+            let t = c as u64 - '0' as u64 + 1;
+            prefix = prefix * base + t;
+            suffix = suffix + t * mul;
+            mul *= base;
+            if prefix == suffix {
+                idx = i + 1;
+            }
+        }
+        if idx == s.len() {
+            s
+        } else {
+            let x: String = (&s[idx..]).chars().rev().collect();
+            String::from(x + &s)
+        }
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0200-0299/0214.Shortest Palindrome/README_EN.md

@@ -132,6 +132,32 @@ func shortestPalindrome(s string) string {
 }
 ```
 
+### **Rust**
+
+```rust
+impl Solution {
+    pub fn shortest_palindrome(s: String) -> String {
+        let base = 131;
+        let (mut idx, mut prefix, mut suffix, mut mul) = (0, 0, 0, 1);
+        for (i, c) in s.chars().enumerate() {
+            let t = c as u64 - '0' as u64 + 1;
+            prefix = prefix * base + t;
+            suffix = suffix + t * mul;
+            mul *= base;
+            if prefix == suffix {
+                idx = i + 1;
+            }
+        }
+        if idx == s.len() {
+            s
+        } else {
+            let x: String = (&s[idx..]).chars().rev().collect();
+            String::from(x + &s)
+        }
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0200-0299/0214.Shortest Palindrome/Solution.rs

@@ -0,0 +1,21 @@
+impl Solution {
+    pub fn shortest_palindrome(s: String) -> String {
+        let base = 131;
+        let (mut idx, mut prefix, mut suffix, mut mul) = (0, 0, 0, 1);
+        for (i, c) in s.chars().enumerate() {
+            let t = c as u64 - '0' as u64 + 1;
+            prefix = prefix * base + t;
+            suffix = suffix + t * mul;
+            mul *= base;
+            if prefix == suffix {
+                idx = i + 1;
+            }
+        }
+        if idx == s.len() {
+            s
+        } else {
+            let x: String = (&s[idx..]).chars().rev().collect();
+            String::from(x + &s)
+        }
+    }
+}