Problem: Write a program which takes as input two arrays of digits representing integers, and returns an integer representing their product. For example, since <1,9,3,7,0,7,7,2,1> x <-7,6,1,8,3,8,2,5,7,2,8,7> = <-1,4,7,5,7,3,9,5,2,5,8,9,6,7,6,4,1,2,9,2,7>.
idea: decoded integers and multiply them, and then encode the result.