add 344

344.Reverse String/344.md

@@ -0,0 +1,20 @@
+#### 344. Reverse String
+>
+>Write a function that reverses a string. The input string is given as an array of characters char[].
+>
+>Do not allocate extra space for another array, you must do this by modifying the input array in-place with O(1) extra memory.
+>
+>You may assume all the characters consist of printable ascii characters.
+>
+> 
+>
+>Example 1:
+>
+>Input: ["h","e","l","l","o"]
+>Output: ["o","l","l","e","h"]
+>Example 2:
+>
+>Input: ["H","a","n","n","a","h"]
+>Output: ["h","a","n","n","a","H"]
+
+

344.Reverse String/rust/reverse_string/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "reverse_string"
+version = "0.1.0"
+authors = ["Jimmy Xiang <[email protected]>"]
+
+[dependencies]

344.Reverse String/rust/reverse_string/src/lib.rs

@@ -0,0 +1,28 @@
+pub fn reverse_string(s: &mut Vec<char>) {
+
+    let n = s.len();
+
+    if n == 0 {
+        return;
+    }
+
+    for i in 0..n/2 {
+            let j = n -1 -i;
+            s[i] = ((s[i] as u8) ^ (s[j] as u8)) as char;
+            s[j] = ((s[i] as u8) ^ (s[j] as u8)) as char;
+            s[i] = ((s[i] as u8) ^ (s[j] as u8)) as char;
+        }
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        let mut test = vec!['x','x','g'];
+        reverse_string(&mut test);
+        assert_eq!(vec!['g','x','x'], test);
+    }
+}