Problem:
Problem H: Eleven Lover

Edward Leven loves multiples of eleven very much. When he sees a number, he always tries
to find consecutive subsequences (or substrings) forming multiples of eleven. He calls such
subsequences as 11-sequences. For example, he can find an 11-sequence 781 in a number 17819.

He thinks a number which has many 11-sequences is a good number. He would like to find out
a very good number. As the first step, he wants an easy way to count how many 11-sequences
are there in a given number. Even for him, counting them from a big number is not easy.
Fortunately, one of his friends, you, is a brilliant programmer. He asks you to write a program
to count the number of 11-sequences. Note that an 11-sequence must be a positive number
without leading zeros.

Input

The input is a sequence of lines each of which contains a number consisting of less than or equal
to 80000 digits.

The end of the input is indicated by a line containing a single zero, which should not be processed.

Output

For each input number, output a line containing the number of 11-sequences.

You can assume the answer fits in a 32-bit signed integer.

Sample Input

17819
1111
11011
1234567891011121314151617181920
0

Output for the Sample Input

1
4
4
38

Solution in Ruby (judge verdict: Accepted)

loop {
	str = gets.chomp
	break if str == ?0

	a = str.each_char.map.with_index {|c, i|
		i.even? ? c.to_i : - c.to_i % 11
	}

	count = Hash.new(0)
	a.inject(0){|s, x|
		s = (s + x) % 11
		count[s] += 1
		s
	}

	total = 0
	a.each{|x|
		total += count[0] if x > 0
		count[x] -= 1
		new_count = {}
		count.each{|y, k|
			new_count[(y - x) % 11] = k
		}
		count = new_count
	}
	p total
}