Preparando MOJI
In Morse code, an letter of English alphabet is represented as a string of some length from $$$1$$$ to $$$4$$$. Moreover, each Morse code representation of an English letter contains only dots and dashes. In this task, we will represent a dot with a "0" and a dash with a "1".
Because there are $$$2^1+2^2+2^3+2^4 = 30$$$ strings with length $$$1$$$ to $$$4$$$ containing only "0" and/or "1", not all of them correspond to one of the $$$26$$$ English letters. In particular, each string of "0" and/or "1" of length at most $$$4$$$ translates into a distinct English letter, except the following four strings that do not correspond to any English alphabet: "0011", "0101", "1110", and "1111".
You will work with a string $$$S$$$, which is initially empty. For $$$m$$$ times, either a dot or a dash will be appended to $$$S$$$, one at a time. Your task is to find and report, after each of these modifications to string $$$S$$$, the number of non-empty sequences of English letters that are represented with some substring of $$$S$$$ in Morse code.
Since the answers can be incredibly tremendous, print them modulo $$$10^9 + 7$$$.
The first line contains an integer $$$m$$$ ($$$1 \leq m \leq 3\,000$$$) — the number of modifications to $$$S$$$.
Each of the next $$$m$$$ lines contains either a "0" (representing a dot) or a "1" (representing a dash), specifying which character should be appended to $$$S$$$.
Print $$$m$$$ lines, the $$$i$$$-th of which being the answer after the $$$i$$$-th modification to $$$S$$$.
3
1
1
1
1
3
7
5
1
0
1
0
1
1
4
10
22
43
9
1
1
0
0
0
1
1
0
1
1
3
10
24
51
109
213
421
833
Let us consider the first sample after all characters have been appended to $$$S$$$, so S is "111".
As you can see, "1", "11", and "111" all correspond to some distinct English letter. In fact, they are translated into a 'T', an 'M', and an 'O', respectively. All non-empty sequences of English letters that are represented with some substring of $$$S$$$ in Morse code, therefore, are as follows.
Although unnecessary for this task, a conversion table from English alphabets into Morse code can be found here.