1358

Author: theforestvn88

1301-1400/1358_number_of_substrings_containing_all_three_characters.rb

@@ -0,0 +1,12 @@
+# @param {String} s
+# @return {Integer}
+def number_of_substrings(s)
+    count = 0
+    last_indexes = [-1,-1,-1]
+    (0...s.length).each { |i|
+        last_indexes[s[i].ord - 97] = i
+        count += last_indexes.min + 1
+    }
+
+    count
+end