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问题 Consider the following snippet: char x[100]; double *p = &x; As expected, this yields this warning: f.c:3:15: warning: initialization of ‘double *’ from incompatible pointer type ‘char (*)[100]’ [-Wincompatible-pointer-types] 3 | double *p = &x; | ^ This is very easy to solve by just changing to double *p = (double*)&x; My question here is, does the casting actually DO anything? Would the code be invalid without the cast? Or is it just a way to make the compiler quiet? When is casting

问题 Here are two programs that naively calculate the number of prime numbers <= n. One is in Python and the other is in Java. public class prime{ public static void main(String args[]){ int n = Integer.parseInt(args[0]); int nps = 0; boolean isp; for(int i = 1; i <= n; i++){ isp = true; for(int k = 2; k < i; k++){ if( (i*1.0 / k) == (i/k) ) isp = false; } if(isp){nps++;} } System.out.println(nps); } } `#!/usr/bin/python` import sys n = int(sys.argv[1]) nps = 0 for i in range(1,n+1): isp = True

问题 Here are two programs that naively calculate the number of prime numbers <= n. One is in Python and the other is in Java. public class prime{ public static void main(String args[]){ int n = Integer.parseInt(args[0]); int nps = 0; boolean isp; for(int i = 1; i <= n; i++){ isp = true; for(int k = 2; k < i; k++){ if( (i*1.0 / k) == (i/k) ) isp = false; } if(isp){nps++;} } System.out.println(nps); } } `#!/usr/bin/python` import sys n = int(sys.argv[1]) nps = 0 for i in range(1,n+1): isp = True

问题 My Question is how can i find minimum and maximum latitude and longitude of specific area (500 meter) from current location. In my case, Such like i need to get X and Y CLLocation (latitude and longitude) from 500 meter of area See my image (sorry for this may be bad drawing ) I also have to tried to googling and i got link such like How can i get minimum and maximum latitude and longitude using current location and radius? But i don't know how it implement in my case. Pleas help me in this

问题 My Question is how can i find minimum and maximum latitude and longitude of specific area (500 meter) from current location. In my case, Such like i need to get X and Y CLLocation (latitude and longitude) from 500 meter of area See my image (sorry for this may be bad drawing ) I also have to tried to googling and i got link such like How can i get minimum and maximum latitude and longitude using current location and radius? But i don't know how it implement in my case. Pleas help me in this

问题 I'm trying to write a converter class for custom types--converting one type (and all of its properties) to another type that has matching properties. The problem comes in when the property is also a custom type, rather that a simple type. The custom types are all identical, except they live in different namespaces in the same solution. TypeTwo objects are Webservice references. For example public TypeOne ConvertToTypeTwo (TypeTwo typeTwo) { var typeOne = new TypeOne(); typeOne.property1 =

问题 My Question is how can i find minimum and maximum latitude and longitude of specific area (500 meter) from current location. In my case, Such like i need to get X and Y CLLocation (latitude and longitude) from 500 meter of area See my image (sorry for this may be bad drawing ) I also have to tried to googling and i got link such like How can i get minimum and maximum latitude and longitude using current location and radius? But i don't know how it implement in my case. Pleas help me in this

问题 I'm trying to deploy an ember app to AWS CloudFront using ember-cli-deploy and ember-cli-deploy-cloudfront. I set up my bucket and user in AWS, gave my user AmazonS3FullAccess policy. Set up my .env.deploy.production file to look like this: AWS_KEY=<my key> AWS_SECRET=<my secret> PRODUCTION_BUCKET=<app.<my domain>.com PRODUCTION_REGION=us-east-1 PRODUCTION_DISTRIBUTION=<my cloudfront distribution id> My config/default.js looks like this: /* jshint node: true */ module.exports = function

问题 I have been using Tkinter from couple of weeks. One thing I have noticed is that the tkinter widgets (Button, etc.) have 3 states: NORMAL , ACTIVE and DISABLED . I understand the NORMAL and DISABLED states. Whats the difference between the ACTIVE and NORMAL states? 回答1: Tk sets state = ACTIVE when a mouse is over a non-DISABLED button option (i.e. NORMAL) It can then be made to appear raised, sunken, flat, flash etc. So basically, NORMAL enables a button while ACTIVE can change the appearance

问题 The If statement and any other boolean comparison is smart enought to stop at first FALSE value when evaluating A and B and C and D and at first TRUE value when evaluating A or B or C or D . What is the name of this behavior? Is this a compiler optimization? If so, there is a way to disable it with some compiler directive? 回答1: This is called 'boolean short-circuit evaluation', a form of 'lazy evaluation'. You can tell the compiler either to use or not to use this feature using compiler