longest_palindrome

Author: u2

src/find_median_sorted_arrays.rs.bk

@@ -2,3 +2,4 @@ pub mod two_sum;
 pub mod add_two_numbers;
 pub mod length_of_longest_substring;
 pub mod find_median_sorted_arrays;
+pub mod longest_palindrome;

src/lib.rs

@@ -0,0 +1,44 @@
+// Brute Force
+pub fn longest_palindrome(input: &str) -> &str {
+    let length = input.len();
+    let mut sub: &str;
+    for i in 0..length {
+        for j in 0..i + 1 {
+            sub = &input[j..length - i + j];
+            if is_palindrome(sub.to_string()) {
+                return sub;
+            }
+        }
+    }
+    return &input[0..0];
+}
+
+pub fn is_palindrome(s: String) -> bool {
+    let mut rs = s.clone().into_bytes();
+    rs.reverse();
+    return rs == s.into_bytes();
+}
+
+#[cfg(test)]
+mod test {
+    use super::is_palindrome;
+    use super::longest_palindrome;
+
+    #[test]
+    fn test_is_palindrome() {
+        assert_eq!(is_palindrome(String::from("aba")), true);
+        assert_eq!(is_palindrome(String::from("ab")), false);
+        assert_eq!(is_palindrome(String::from("a")), true);
+        assert_eq!(is_palindrome(String::from("abab")), false);
+    }
+
+    #[test]
+    fn test_longest_palindrome() {
+        assert_eq!(longest_palindrome("babad"), "bab");
+        assert_eq!(longest_palindrome("abccba"), "abccba");
+        assert_eq!(longest_palindrome("cabccbad"), "abccba");
+        assert_eq!(longest_palindrome("xbacabccbaddab"), "abccba");
+        assert_eq!(longest_palindrome("abccbaddxe"), "abccba");
+        assert_eq!(longest_palindrome("ddxeabccba"), "abccba");
+    }
+}