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Apr
1
comment Is (1/(1/x)) always a perfect round trip?
You cannot conclude from the fact that 1/x can't be represented exactly that 1/(1/x) != x. To take your example, in 3.s.f. decimal floating point, 1.00 / 3.00 = 0.333, and 1.00 / 0.333 is 3.00. That particular mantissa is a fixed point of the double-reciprocal in that floating point scheme.
Mar
21
comment Why interviewers want Optimal Algorithms
Are you sure they were doubtful about the correctness and not just wanting to see how clearly you were capable of explaining its working?
Mar
20
comment Login on every page requires SSL on all pages
FWIW some XSS vectors would allow the attacker to send information to an attacker-controlled site even if the page with the login form is only sent over HTTPS.
Feb
27
comment Validating Emails in PHP
@AmgadSuliman, probably not, but if you download IsEmail you can use its test suite to check most if not all of the corner cases.
Feb
27
answered Validating Emails in PHP
Feb
26
comment Tineye.com search algorithm?
@ScottWhitlock, there is an obvious approach to the problem, which is wavelet compression followed by quantising and prefix matching. Whether that's what tineye uses, I don't know.
Feb
18
awarded  Caucus
Feb
16
comment How does if/else work internally in all programming languages?
@Neil, depends on the processor's instruction set. ARM has some interesting stuff with conditional instructions.
Feb
10
answered Committing https certificates to Github…is there ever a good reason for this?
Feb
6
comment Why use partial classes?
Mixins. This could be combined with T4 to avoid manual copying...
Jan
14
awarded  Yearling
Jan
2
comment Evaluate math expressions without a stack
The approach of factoring out the a*b term works mathematically, assuming that we're using real numbers, rational numbers, or something structurally similar. But it wouldn't necessarily give the same result if we're using float, and it certainly wouldn't give the same result if we're using int (e.g. 7/2*2 gives 6). The question doesn't say what it's using, but from the comments it's definitely using int.
Jan
2
comment Evaluate math expressions without a stack
This assumes operation over a field, which isn't stated in the question and is unlikely in practice (as neither the integers nor IEEE-854 floating point representations are fields).
Jan
2
comment Evaluate math expressions without a stack
@Blrfl, I think the idea is to use a more powerful machine as the compiler.
Dec
21
comment Are all security threats triggered by software bugs?
@JoachimSauer, what if your website refuses to transfer any information over HTTP and it's actually a MITM who's mapping HTTP to HTTPS? While browsers support HTTP and routers permit it to pass there's a vulnerability to sniffing which can only be avoided by extremely security-conscious clients. So really the question becomes: is it a bug for web browsers to support HTTP?
Dec
18
answered Matrix Pattern Recognition Algorithm
Dec
17
answered Chambers In A Castle Algorithm
Dec
1
comment Should I encrypt data in database?
The user is going to log on with their password and then have access to the data, so the data is no more secure than the user's password no matter what method you use to get from password to key. You should refuse to allow the user to set their password to 12345 with an entropy checker which takes into account simple patterns (e.g. port zxcvbn).
Dec
1
comment Is there a rule of thumb for what a bing map's zoom setting should be based on how many miles you want to display?
Taking into account wrapping of longitude if the use cases are likely to include sets of points in the Pacific.
Nov
27
comment Usefull skills from a computer science degree
Most of what is covered in a CS degree has no direct application in 90% of "real life" programming. Contrariwise, many of the important topics in being a good programmer aren't covered by a CS degree.