3517. 最小回文排列 I

src/main.rs

@@ -1,32 +1,32 @@
-use std::collections::HashMap;
-
 mod arr;
 struct Solution {}
 impl Solution {
-    pub fn array_rank_transform(mut arr: Vec<i32>) -> Vec<i32> {
-        if arr.len() == 0 {
-            return arr;
+    pub fn smallest_palindrome(s: String) -> String {
+        let mut arr = vec![0; 26];
+        let mut s = s.chars().collect::<Vec<char>>();
+        for i in 0..s.len() / 2 {
+            arr[(s[i] as u8 - b'a') as usize] += 1;
         }
-        let mut sorted_arr = arr.clone();
-        sorted_arr.sort_unstable();
-        let mut mp = HashMap::with_capacity(arr.len());
-        let mut sub = 0;
-        mp.insert(sorted_arr[0], 0);
-        for i in 1..sorted_arr.len() {
-            if sorted_arr[i] == sorted_arr[i-1] {
-                sub+=1;
-                continue;
+        let mut idx = 0;
+        for i in 0..26 {
+            while arr[i] > 0 {
+                s[idx] = (b'a' + i as u8) as char;
+                arr[i] -= 1;
+                idx += 1;
             }
-            mp.insert(sorted_arr[i], i as i32 - sub);
         }
-        println!("{:?}", mp);
-        for x in arr.iter_mut() {
-             *x = *mp.get(x).unwrap() + 1;
+        let mut rev_idx = idx;
+        if s.len() % 2 != 0{
+            idx += 1;
         }
-        arr
+        while rev_idx > 0{
+            rev_idx -= 1;
+            s[idx] = s[rev_idx];
+            idx += 1;
+        }
+        s.into_iter().collect::<String>()
     }
 }
-
 fn main() {
-    println!("{:?}", Solution::array_rank_transform(vec![1,5,2,3,4,5]));
+    println!("{:?}", Solution::smallest_palindrome("bahaahab".to_string()));
 }