How many integers can I create in 1GB memory?

Question

In book Algorithms fourth edition by Robert Sedgewick on page 200, it says "for example, if you have 1GB of memory on your computer (1 billion bytes), you cannot fit more than about 32 million int values."

I got confused after my calculation: 1,000,000,000 bytes/4 bytes = 250 million

How the author got 32 million?

The book describes like below:

Don't mix bits and bytes and also there is a difference between signed and unsigned integers. — mkabanen, Feb 22 '16 at 10:14
no difference between signed and unsigned in the scope of this question — Evgeniy Mishustin, Feb 22 '16 at 10:17
@MargaretBloom yes, I know the difference. But the author write on page very clear, GB not GiB — Max, Feb 22 '16 at 10:18
Possible duplicate of [Java Memory usage - primitives](http://stackoverflow.com/questions/18278010/java-memory-usage-primitives) — stephan, Feb 22 '16 at 10:20
Well if they made a *mistake* and intended "*for example, if you have **1Gib** of memory on your computer (**about** 1 billion **bits**), you cannot fit more than about 32 **Mi** int values.*" (additions and edits mine) everything would work. — Margaret Bloom, Feb 22 '16 at 10:25
@MargaretBloom if so, it is 1,000,000,000 bits/ 32 bits = 31 million. There is no need to write as 32 million, which is still wrong. — Max, Feb 22 '16 at 10:28
That's because books have errors all the time. [And they acknowledge them](http://algs4.cs.princeton.edu/errata/errata-printing3.php) — n. m. could be an AI, Feb 22 '16 at 10:49

Max · Accepted Answer · 2018-04-05T00:55:17.593

7

The author has acknowledged that this is an error in this book website, please refer to the link as follows: http://algs4.cs.princeton.edu/errata/errata-printing3.php

edited Apr 05 '18 at 00:55

answered Feb 22 '16 at 22:19

Max

1,012
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score 5 · Answer 2 · answered Feb 22 '16 at 10:41

5

1 gigabit = 1073741824 bit
1 int = 32 bit
calculation = (1073741824/32) = (32 * 1024²) = (32 * 2²⁰) = 32 million

If author meant gigabytes then answer would be (32 * 8) million = 256 million

answered Feb 22 '16 at 10:41

shaggy007

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8

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`32 * 2^20 = 33.554.432 != 32000000 = 32*10^6 = 32 millions`. Please use the correct terminology. – Margaret Bloom Feb 22 '16 at 10:44
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In binary systems 1k = 1024, 1M = 1024k = 1024 * 1024 = 2^20 so here 32 million or 32 Mega = 32 * 2^20 here only unit is not present , i. e. bit – shaggy007 Feb 22 '16 at 11:02
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*M* is a standard [ISU](https://en.wikipedia.org/wiki/International_System_of_Units) suffix that means `10^6`. **For whatever computation you are doing, in any base**. For long time it **had** a special meaning for CS and that gave rise to ambiguities (never have bought an HDD?) , but now the problem has been settled with the binary suffix *Mi* (2^20). Perpetuating an old misleading use is dangerous. So please, use the correct terminology. – Margaret Bloom Feb 22 '16 at 11:18

score 0 · Answer 3 · answered Aug 27 '22 at 07:30

0

Answer is 268405456 we can fit in 1 gb

How ? Let's find out

Int size is 4 byte

1kb  can conation =1024/4=256 int number.
 1mb can store=256*1024=262144
 1gb can store=262144*1024=268405456  int  value

answered Aug 27 '22 at 07:30

Pankaj Mehta

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How many integers can I create in 1GB memory?

3 Answers3

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