diff --git a/Utils/StringUtils.php b/Utils/StringUtils.php
index 087760ae0..025561901 100644
--- a/Utils/StringUtils.php
+++ b/Utils/StringUtils.php
@@ -337,7 +337,7 @@ final class StringUtils
                 break;
             }
 
-            $count++;
+            ++$count;
         }
 
         return $count;
@@ -426,4 +426,70 @@ final class StringUtils
             return $element->__toString();
         }
     }
+
+    public static function computeLCSDiff(string $from, string $to) : array
+    {
+        $diffValues = [];
+        $diffMask   = [];
+
+        $dm = [];
+        $n1 = \count($from);
+        $n2 = \count($to);
+
+        for ($j = -1; $j < $n2; $j++) {
+            $dm[-1][$j] = 0;
+        }
+
+        for ($i = -1; $i < $n1; $i++) {
+            $dm[$i][-1] = 0;
+        }
+
+        for ($i = 0; $i < $n1; $i++) {
+            for ($j = 0; $j < $n2; $j++) {
+                if ($from[$i] == $to[$j]) {
+                    $ad = $dm[$i - 1][$j - 1];
+                    $dm[$i][$j] = $ad + 1;
+                }
+                else {
+                    $a1 = $dm[$i - 1][$j];
+                    $a2 = $dm[$i][$j - 1];
+                    $dm[$i][$j] = \max($a1, $a2);
+                }
+            }
+        }
+
+        $i = $n1 - 1;
+        $j = $n2 - 1;
+        while (($i > -1) || ($j > -1)) {
+            if ($j > -1) {
+                if ($dm[$i][$j - 1] == $dm[$i][$j]) {
+                    $diffValues[] = $to[$j];
+                    $diffMask[]   = 1;
+                    --$j;
+
+                    continue;
+                }
+            }
+
+            if ($i > -1) {
+                if ($dm[$i - 1][$j] == $dm[$i][$j]) {
+                    $diffValues[] = $from[$i];
+                    $diffMask[]   = -1;
+                    --$i;
+
+                    continue;
+                }
+            }
+
+            $diffValues[] = $from[$i];
+            $diffMask[] = 0;
+            --$i;
+            --$j;
+        }
+
+        $diffValues = \array_reverse($diffValues);
+        $diffMask   = \array_reverse($diffMask);
+
+        return ['values' => $diffValues, 'mask' => $diffMask];
+    }
 }