create 2002 in rust

rust/2002-maximum-product-of-the-length-of-two-palindromic-subsequences.rs

@@ -0,0 +1,55 @@
+impl Solution {
+ pub fn max_product(s: String) -> i32 {
+ let s: Vec<char> = s.chars().collect();
+ let mut s1 = vec![];
+ let mut s2 = vec![];
+ let mut res = 0;
+
+ Solution::dfs(&s, &mut s1, &mut s2, &mut res, 0);
+
+ res
+ }
+
+ fn dfs(s: &[char], s1: &mut Vec<char>, s2: &mut Vec<char>, res: &mut i32, index: usize) {
+ // Base case
+ if index == s.len() {
+ if Solution::is_palindrome(s1) && Solution::is_palindrome(s2) {
+ let new_max = s1.len() * s2.len();
+ *res = std::cmp::max(*res, new_max as i32);
+ }
+ return;
+ }
+
+ // Option 0: Not in S1 nor S2
+ Solution::dfs(s, s1, s2, res, index + 1);
+
+ // Option 1: in S1
+ s1.push(s[index]);
+ Solution::dfs(s, s1, s2, res, index + 1);
+ s1.pop();
+
+ // Option 2: in S2
+ s2.push(s[index]);
+ Solution::dfs(s, s1, s2, res, index + 1);
+ s2.pop();
+ }
+
+ fn is_palindrome(s: &[char]) -> bool {
+ if s.len() <= 1 {
+ return true;
+ }
+
+ let mut l = 0;
+ let mut r = s.len() - 1;
+
+ while l < r {
+ if s[l] != s[r] {
+ return false;
+ }
+ l += 1;
+ r -= 1;
+ }
+
+ true
+ }
+}