0003

Author: ruoru

Algorithms/0003.longest_substring_without_repeating_characters/longest_substring_without_repeating_characters.rs

@@ -1,48 +1,30 @@
 use std::cmp::max;
+use std::collections::HashMap;
+
+pub struct Solution {}
 
 impl Solution {
     pub fn length_of_longest_substring(s: String) -> i32 {
-    let mut start = 0;
-    let mut end = 0;
-
-    let s_length = s.len();
-    let mut sub_strings: Vec<char> = vec![];
-
-    let mut result = 0;
-
-    while end < s_length {
-        let c = s.chars().nth(end).unwrap();
-
-        let mut loop_finish = true;
-        let mut i = 0;
-        for vv in sub_strings.iter() {
-            if vv == &c {
-                start = i + start + 1;
-                end = start - 1;
-                loop_finish = false;
-                sub_strings = vec![];
-                break;
+        let mut index = 0;
+        let mut prev_index = -1;
+        let mut result = 0;
+        let mut sub_strings: HashMap<char, i32> = HashMap::new();
+
+        for c in s.chars() {
+            match sub_strings.get(&c) {
+                None => {}
+                Some(p_ind) => {
+                    if prev_index < *p_ind {
+                        prev_index = *p_ind;
+                    }
+                }
             }
-            i += 1;
-        }
 
-        if loop_finish {
-            sub_strings.push(c);
+            result = max(result, index - prev_index);
+            sub_strings.insert(c, index);
+            index += 1;
         }
 
-        end += 1;
-        result = max(result, end - start);
+        return result as i32;
     }
-
-    return result as i32;
-    }
-}
-
-
-
-fn main() {
-    let s = String::from("Hello world");
-    let result = longest_substring_without_repeating_characters(s);
-
-    println!("{}", result);
 }