From cc9d3de6c4f8edf2813852a26c332cf906fd1c17 Mon Sep 17 00:00:00 2001
From: Shreeman Arjun Sahu <shreemanarjunsahu@gmail.com>
Date: Wed, 18 Dec 2024 23:39:23 +0530
Subject: [PATCH] `Refactor Levenshtein distance calculation in code.dart`

---
 levenshtein/dart/code.dart | 57 +++++++++++++++++++++++---------------
 1 file changed, 34 insertions(+), 23 deletions(-)

diff --git a/levenshtein/dart/code.dart b/levenshtein/dart/code.dart
index 2cda0ec3..2aad4377 100644
--- a/levenshtein/dart/code.dart
+++ b/levenshtein/dart/code.dart
@@ -4,28 +4,38 @@ int levenshteinDistance(String word1, String word2) {
   final m = word1.length;
   final n = word2.length;
   // Create a matrix to store distances
-  var matrix = List.generate(m+1, (i) => List.generate(n+1, (j) => 0));
+  var matrix = List.generate(
+      m + 1,
+      (i) => List.generate(
+            n + 1,
+            (j) => 0,
+            growable: false,
+          ),
+      growable: false);
 
-  // Initialize first row and column 
+  // Initialize first row and column
   for (int i = 1; i <= m; i++) {
-      matrix[i][0] = i;
+    matrix[i][0] = i;
   }
   for (int j = 1; j <= n; j++) {
-      matrix[0][j] = j;
+    matrix[0][j] = j;
   }
-  
+
   // Compute Levenshtein distance
   for (int i = 1; i <= m; i++) {
-      for (int j = 1; j <= n; j++) {
-        int cost = word1[i-1] == word2[j-1]? 0:1;
-        matrix[i][j] = min(
-            min(
-                matrix[i-1][j] + 1, // Deletion
-                matrix[i][j-1] + 1  // Insertion
-            ),
-            matrix[i-1][j-1] + cost // Substitution
-        );
-      }
+    final a = matrix[i];
+    final b = matrix[i - 1];
+    final c = word1[i - 1];
+    for (int j = 1; j <= n; j++) {
+      int cost = c == word2[j - 1] ? 0 : 1;
+      a[j] = min(
+          min(
+              b[j] + 1, // Deletion
+              a[j - 1] + 1 // Insertion
+              ),
+          b[j - 1] + cost // Substitution
+          );
+    }
   }
   return matrix[m][n];
 }
@@ -40,15 +50,16 @@ void main(List<String> args) {
   int times = 0;
   // Compare each pair of arguments exactly once
   for (int i = 0; i < args.length; i++) {
-      for (int j = i+1; j < args.length; j++) {
-        if (i != j) {
-            int distance = levenshteinDistance(args[i], args[j]);
-            if (minDistance == -1 || distance < minDistance ) {
-                minDistance = distance;
-            }
-            times++;
+    final a = args[i];
+    for (int j = i + 1; j < args.length; j++) {
+      if (i != j) {
+        int distance = levenshteinDistance(a, args[j]);
+        if (minDistance == -1 || distance < minDistance) {
+          minDistance = distance;
         }
+        times++;
       }
+    }
   }
 
   // The only output from the program should be the times (number of comparisons)
@@ -56,4 +67,4 @@ void main(List<String> args) {
   // formatted exactly like this.
   print("times: " + times.toString());
   print("min_distance: " + minDistance.toString());
-}
\ No newline at end of file
+}