Will someone explain the BIT_AR problem of Overnight Coding and also how to solve it? Here is the problem link. asked 18 Feb, 18:41

It says that let A denote the array of distinct characters in the given string sorted in the order of their position of the first occurrence. The question asked only to find the number of different ways this array occurs in the given string as subsequence modulo 1000000007 answered 18 Feb, 18:52
