lookup-tables

问题 In another thread, I was told that a switch may be better than a lookup table in terms of speed and compactness. So I'd like to understand the differences between this: Lookup table static void func1(){} static void func2(){} typedef enum { FUNC1, FUNC2, FUNC_COUNT } state_e; typedef void (*func_t)(void); const func_t lookUpTable[FUNC_COUNT] = { [FUNC1] = &func1, [FUNC2] = &func2 }; void fsm(state_e state) { if (state < FUNC_COUNT) lookUpTable[state](); else ;// Error handling } and this:

问题 Are there any good webservices out there that provide good lookup information for Countries and States/Provinces? If so what ones do you use? 回答1: If you only need US information, the US Postal Service provides a set of web services it calls WebTools for this exact thing. https://www.usps.com/business/web-tools-apis/welcome.htm. You will need to register to be able to use them but once you're registered they are really simple to use. You just send an XML request over HTTP and the server sends

问题 I have some function which maps some input to the output . The output is a complex number. What I'm actually interested in is the inverse function . But since this inversion can't be done in a analytical way I need to do it with a numerical approximation. Since is computationally expensive my idea was to use a lookup table approach. I can generate a 2D lookup table with the dimensions (forward lookup table), but what I actually need is the inverse of this lookup table—yielding based on a

问题 Closed . This question needs to be more focused. It is not currently accepting answers. Want to improve this question? Update the question so it focuses on one problem only by editing this post. Closed 5 years ago . I am using vba macros. Task: 1) User will give two inputs viz. number of devices sold (column B) and week number (column A). 2) Search the excel file using these two and get the earnings. (Conditions: 1. We dont have to modify anything in the excel file. 2.And we have to first