fixing checkstyle suppression patterns to work with Windows paths
diff --git a/src/main/resources/checkstyle/checkstyle-suppressions.xml b/src/main/resources/checkstyle/checkstyle-suppressions.xml
index 8b74a51..ee631c4 100644
--- a/src/main/resources/checkstyle/checkstyle-suppressions.xml
+++ b/src/main/resources/checkstyle/checkstyle-suppressions.xml
@@ -19,10 +19,10 @@
     "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
     "https://checkstyle.org/dtds/suppressions_1_2.dtd">
 <suppressions>
-  <suppress checks="Indentation" files=".*/combinatorics/Factorial.java" />
-  <suppress checks="ParameterNumber" files=".*/arrays/LinearCombination.java" />
-  <suppress checks="FileLengthCheck" files=".*/Complex(Test)?.java" />
-  <suppress checks="MethodLength" files=".*/Complex.java" />
+  <suppress checks="Indentation" files=".*[/\\]combinatorics[/\\]Factorial\.java" />
+  <suppress checks="ParameterNumber" files=".*[/\\]arrays[/\\]LinearCombination\.java" />
+  <suppress checks="FileLengthCheck" files=".*[/\\]Complex(Test)?\.java" />
+  <suppress checks="MethodLength" files=".*[/\\]Complex\.java" />
 
   <!-- Be more lenient on tests. -->
   <suppress checks="Javadoc" files=".*[/\\]test[/\\].*" />