update 2683

theforestvn88 · theforestvn88 · commit 1391259b163e · 2025-01-18T11:06:06.000+07:00
diff --git a/2601-2700/2683_neighboring_bitwise_xor.rb b/2601-2700/2683_neighboring_bitwise_xor.rb
@@ -1,5 +1,8 @@
 # @param {Integer[]} derived
 # @return {Boolean}
 def does_valid_array_exist(derived)
+    # assume the original is [a,b,c,d]
+    # the derived will be: [(a^b),(b^c),(c^d),(d^a)]
+    # hence the xor-sum (a^b^b^c^c^d^d^a) will be zero 
     derived.reduce(&:^).zero?
 end
