3208

theforestvn88 · theforestvn88 · commit 5c58ae372240 · 2025-03-09T15:29:51.000+07:00
diff --git a/3201-3300/3208_alternating_groups_ii.rb b/3201-3300/3208_alternating_groups_ii.rb
@@ -0,0 +1,19 @@
+# @param {Integer[]} colors
+# @param {Integer} k
+# @return {Integer}
+def number_of_alternating_groups(colors, k)
+    count = 0
+    alter_length = 0
+    size = colors.size
+    # concat 2 colors to deal with circular
+    (0...2*size).each { |i|
+        if colors[i % size] != colors[(i-1) % size]
+            alter_length += 1
+            # to avoid counting duplicate groups, only count from the second colors
+            count += 1 if alter_length >= k && i >= size
+        else
+            alter_length = 1
+        end
+    }
+    count
+end
