Improved problem 5 runtime, removed unneeded TODO from problem 15

src/bin/15_3sum.rs

@@ -4,7 +4,6 @@ fn main() {
     println!("{:?}", three_sum(vec![-2,0,0,2,2]));
 }
 
-// TODO: fix and optimize
 pub fn three_sum(mut nums: Vec<i32>) -> Vec<Vec<i32>> {
     let mut result = Vec::<Vec<i32>>::new();
     nums.sort();

src/bin/16_3sum_closest.rs

@@ -0,0 +1,8 @@
+fn main() {
+
+}
+
+pub fn three_sum_closest(nums: Vec<i32>, target: i32) -> i32 {
+    
+    return 0;
+}

src/bin/5_longest_palindrome_substring.rs

@@ -1,21 +1,17 @@
 fn main() {
-    println!("{}", longest_palindrome(String::from("bccd")));
+    println!("{}", longest_palindrome(String::from("bb")));
 }
 
 pub fn longest_palindrome(s: String) -> String {
-    if s.len() <= 1 { return s; }
-    let mut longest_palindrome = String::from(&s[0..1]);
-    for i in 0..s.len()-1 {
-        for even_palindrome_offset in 0..=1 {
-            let (mut start, mut end) = (i + even_palindrome_offset, i);
+    let mut max_indexes = (0usize, 1usize);
+    for i in 0..(s.len()-1)*2 {
+        let (mut start, mut end) = (i / 2 + i % 2, i / 2);
         while start > 0 && end < s.len() - 1 {
             if s.as_bytes()[start - 1] != s.as_bytes()[end + 1] { break; }
             start -= 1; end += 1;
         }
-            if end + 1 - start > longest_palindrome.len() {
-                longest_palindrome = String::from(&s[start..end+1]);
+        let length = end + 1 - start;
+        if length > max_indexes.1 - max_indexes.0 { max_indexes = (start, end + 1); }
     }
-        }
-    }
-    return longest_palindrome;
+    return String::from(&s[max_indexes.0..max_indexes.1]);
 }