Not everything in the real world appreciates the holy computer numbers. These are binary values that parallel the powers of 2: 1, 2, 4, 8, 16, 32, 64, and so on.<\/p>\n
A common computer puzzle is how to allocate storage specific to those holy numbers, especially when the sizes of items that you’re working with don’t exactly line up to a specific holy computer number.
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\nFor example, suppose you have a string of 11 bytes. You might create a storage container 16 bytes wide to hold those bytes. You don’t have to do so, but when you built a 16-byte buffer, the processor can more effectively access the information.<\/p>\n
Internally, the compiler prefers to align values at specific memory locations. If you use a debugger, you’ll see how variables sit at address offsets that end in 0, 4, 8, and C. This is why in my code I set buffer sizes to a holy number. It’s not a requirement, but the practice uses memory more efficiently.<\/p><\/blockquote>\n
To put it another way, suppose that you’re tasked with organizing a pile of 2-by-4s. Each board is a different length, but you must set them into containers that are exactly 16, 32, 48, and 64 inches tall. So you would take a 15-inch long board and put it into the 16-inch tall container. The 39-inch board would fit into the 48-inch cubby, and so on.<\/p>\n
For this month’s Exercise, you start with an int<\/em> array of values:<\/p>\n
int lengths[COUNT] = { 4, 28, 52, 16, 35 };<\/code><\/pre>\nYour job is to process each of the
COUNT<\/code> (five) values to determine how they best-fit into a container that is a multiple of 16 units in size.<\/p>\nObviously, I don’t want you to create a single 64-unit container and just stick everything into it. That’s not the solution. In fact, here’s the output from my solution:<\/p>\n
Length of 4 fits into 16\r\nLength of 28 fits into 32\r\nLength of 52 fits into 64\r\nLength of 16 fits into 16\r\nLength of 35 fits into 48<\/code><\/pre>\nYour solution must determine which multiple of 16 is closest to the value given and set a container size accordingly. Your code must also detect when a value is identical to a multiple of 16 and set the value to match.<\/p>\n
Please try this Exercise on your own before you check out my solution<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"
Allocate enough storage space for various sizes of data. Continue reading