Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 719
  • Last Modified:

Compress data using C++

Hi Experts,

I am new to C++ and need to come up with some sort of solution. Please see below:
The following data is a time series of integer values

int timeseries[32] = {67497, 67376, 67173, 67235, 67057, 67031, 66951,
66974, 67042, 67025, 66897, 67077, 67082, 67033, 67019, 67149, 67044, 67012,
67220, 67239, 66893, 66984, 66866, 66693, 66770, 66722, 66620, 66579, 66596,
66713, 66852, 66715};
 
The series might be, for example, the closing price of a stock each day over a 32 day period.

As stored above, the data will occupy 32 x sizeof(int) bytes = 128 bytes assuming 4 byte ints.

Using delta encoding  in need to write a function to compress, and a function to uncompress data like the above.
 
Can you help? Speedy response is very much appreciated!
0
motolanix1
Asked:
motolanix1
1 Solution
 
Jaime OlivaresSoftware ArchitectCommented:
Homework?

since stock values use to have just little variations, you can calculate minimum value of all these, then calculate the deltas, so value can fit a 8 bits (1byte) or 16 bits variables (2bytes). Having determined the deltas and the required capacity, create an byte array with the required capacity plus five, by example:

compressed size = 32 x 2 + 5 = 69 bytes

then, at first byte, store the required capacity in bytes (1, 2 or 4), at the following 4-byte store the minimum value, and in the following byte the data itself.

0
 
alexcohnCommented:
Many open source / free compression libraries are available. Maybe the simplest solution is described here: http://www.codeproject.com/KB/files/zip_utils.aspx.
0

Featured Post

Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Tackle projects and never again get stuck behind a technical roadblock.
Join Now