Remove kruft, make more idiomatic

levenshtein/rust/code.rs

@@ -3,54 +3,38 @@ use std::env;
 /// Calculates the Levenshtein distance between two strings using Wagner-Fischer algorithm
 /// Space Complexity: O(min(m,n)) - only uses two rows instead of full matrix
 /// Time Complexity: O(m*n) where m and n are the lengths of the input strings
-fn levenshtein_distance(s1: &str, s2: &str) -> usize {
-    // Early termination checks
-    if s1 == s2 {
-        return 0;
-    }
-    if s1.is_empty() {
-        return s2.len();
-    }
-    if s2.is_empty() {
-        return s1.len();
-    }
-
-    // Convert to bytes for faster access
-    let s1_bytes = s1.as_bytes();
-    let s2_bytes = s2.as_bytes();
-
-    // Make s1 the shorter string for space optimization
-    let (s1_bytes, s2_bytes) = if s1_bytes.len() > s2_bytes.len() {
-        (s2_bytes, s1_bytes)
+fn levenshtein_distance(s1: &[u8], s2: &[u8]) -> usize {
+    let (s1_bytes, s2_bytes) = if s1.len() > s2.len() {
+        (s2, s1)
     } else {
-        (s1_bytes, s2_bytes)
+        (s1, s2)
     };
 
     let m = s1_bytes.len();
     let n = s2_bytes.len();
 
     // Use two rows instead of full matrix for space optimization
-    let mut prev_row = Vec::with_capacity(m + 1);
-    let mut curr_row = Vec::with_capacity(m + 1);
-
-    // Initialize first row
-    prev_row.extend(0..=m);
-    curr_row.resize(m + 1, 0);
+    let mut prev_row = vec![0; m + 1];
+    let mut curr_row = vec![0; m + 1];
 
     // Main computation loop
     for j in 1..=n {
         curr_row[0] = j;
 
         for i in 1..=m {
-            let cost = if s1_bytes[i - 1] == s2_bytes[j - 1] { 0 } else { 1 };
-
+            let cost = if s1_bytes[i - 1] == s2_bytes[j - 1] {
+                0
+            } else {
+                1
+            };
+
             // Calculate minimum of three operations
             curr_row[i] = std::cmp::min(
                 std::cmp::min(
-                    prev_row[i] + 1,      // deletion
-                    curr_row[i - 1] + 1,  // insertion
+                    prev_row[i] + 1,     // deletion
+                    curr_row[i - 1] + 1, // insertion
                 ),
-                prev_row[i - 1] + cost    // substitution
+                prev_row[i - 1] + cost, // substitution
             );
         }
 
@@ -76,7 +60,7 @@ fn main() {
     for i in 0..args.len() {
         for j in 0..args.len() {
             if i != j {
-                let distance = levenshtein_distance(&args[i], &args[j]);
+                let distance = levenshtein_distance(args[i].as_bytes(), args[j].as_bytes());
                 if let Some(current_min) = min_distance {
                     if distance < current_min {
                         min_distance = Some(distance);