
ZOJ Problem Set  1493
One of the widelyused technologies in voice signal compression is DPCM encoding.
The algorithm is very simple, yet it's quite effective in signal transferring.
with the initial condition: a0 = b0 = 0, where ai is an 8bit unsigned integer
and bi is a 4bit signed integer, the highest bit is used to represent its sign.
The input consists of several cases, each starts with an even number n (n <=
10000), indicating the number of the bytes to be processed, then followed by
n bytes in hex form.
For each test case, output the number of bytes in DPCM in a line, then output the n bytes in hex form, with 8 numbers per line.
3
Author: TANG, Jiqing Source: ZOJ Monthly, February 2003 