fix: correct file content encoding (#3)

src/main/java/com/example/util/SubtractFunction.java

@@ -1 +1,15 @@
-cGFja2FnZSBjb20uZXhhbXBsZS51dGlsOwoKcHVibGljIGNsYXNzIFN1YnRyYWN0RnVuY3Rpb24gaW1wbGVtZW50cyBDYWxjRnVuY3Rpb24gewoKICAgIHB1YmxpYyBkb3VibGUgY2FsYyhkb3VibGUuLi4gaW5wdXQpIHsKICAgICAgICBpZiAoaW5wdXQubGVuZ3RoID09IDApIHsKICAgICAgICAgICAgcmV0dXJuIDA7CiAgICAgICAgfQogICAgICAgIGRvdWJsZSByZXN1bHQgPSBpbnB1dFswXTsKICAgICAgICBmb3IgKGludCBpID0gMTsgaSA8IGlucHV0Lmxlbmd0aDsgaSsrKSB7CiAgICAgICAgICAgIHJlc3VsdCAtPSBpbnB1dFtpXTsKICAgICAgICB9CiAgICAgICAgcmV0dXJuIHJlc3VsdDsKICAgIH0KfQo=
+package com.example.util;
+
+public class SubtractFunction implements CalcFunction {
+
+    public double calc(double... input) {
+        if (input.length == 0) {
+            return 0;
+        }
+        double result = input[0];
+        for (int i = 1; i < input.length; i++) {
+            result -= input[i];
+        }
+        return result;
+    }
+}