Suppose there is a triangle of digits like the following:
74932
1325
457
92
1
Each digit, with the exception of those in the top row, is equal to the last digit of the sum of
its upper and upperright neighboring digits.
You will be given a String[] questionMarkTriangle containing a triangle where
only one digit in each row is known and all others are represented by '?'s
(see example 0 for clarification).
Each element of questionMarkTriangle represents a row of the triangle, and the rows are given
from top to bottom. Each element contains exactly one digit ('0''9') and
the remaining characters are all '?'s. Restore the triangle and return it as a
String[] without '?'s.
