numbers | 易学教程

Equal loading for parallel task distribution

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问题 I have a large number of independent tasks I would like to run, and I would like to distribute them on a parallel system such that each processor does the same amount of work, and maximizes my efficiency. I would like to know if there is a general approach to finding a solution to this problem, or possibly just a good solution to my exact problem. I have T=150 tasks I would like to run, and the time each task will take is t=T. That is, task1 takes 1 one unit of time, task2 takes 2 units of

Valid batch file variable names?

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问题 I have the following problem with batch files. I simplify the problem below. Running the following batch file, foo.bat, returns word in standard out (in this case, command prompt window) instead of hey . foo.bat @SET 1word="hey" @ECHO %1word% However, executing echo %1word% from the command line returns hey . Is there a reason this should/might be the case? Are numbers not allowed to prefix environment variable names? 回答1: You can create and use environment variables with names that begin

How to split big numbers?

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问题 I have a big number, which I need to split into smaller numbers in Python. I wrote the following code to swap between the two: def split_number (num, part_size): string = str(num) string_size = len(string) arr = [] pointer = 0 while pointer < string_size: e = pointer + part_size arr.append(int(string[pointer:e])) pointer += part_size return arr def join_number(arr): num = "" for x in arr: num += str(x) return int(num) But the number comes back different. It's hard to debug because the number

Remove a decimal place in PHP

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问题 In PHP, I am getting numbers from a database with 3 decimal places. I want to remove the last decimal point. So 2.112 will become 2.11, 23.123 will become 23.12 and 123.267 will become 123.26. Its like doing a floor at a decimal level. 回答1: You can use number_format , you specify the number of decimal places as the second arugment. Example $number = 534.333; echo number_format($number,2) // outputs 534.33 Or use round $number = 549.333; echo round($number, 2) // outputs 534.33 Seems like

How to define that float is half of the number?

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问题 What would be the most efficient way to say that float value is half of integer for example 0.5, 1.5, 10.5? First what coming on my mind is: $is_half = (($number - floor($number)) === 0.5); Is there any better solutions? 回答1: Due to floating point precision errors, you usually should check to see that the difference is below some low amount (but note that 0.5 is representable exactly, so it shouldn't be a problem, but it is in general with floats). So your code is good for your specific sense

Compressing Numbers: Reading Error

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问题 I am using this function for compression of Numbers: unsigned char *MyCompress(unsigned int num, unsigned char *buffer){ int i = 0; unsigned int r = num; unsigned char temp; unsigned char s[5]; printf("received %d to compress\n", num); if(!r){ *buffer++ = 0; return buffer; } while (r){ s[i] = r & 127; r >>= 7; printf("s[%d]=%d; r=%d\n", i, s[i], r); i++; } while (--i >= 0){ temp = (unsigned char)(s[i] | (i ? 128 : 0)); printf("temp=%d\n", temp); *buffer++=temp; } return buffer; } //Now

simple number series

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问题 This is a simple number series question, I have numbers in series like 2,4,8,16,32,64,128,256 these numbers are formed by 2,2(square),2(cube) and so on. Now if I add 2+4+8 = 14 . 14 will get only by the addition 2,4 and 8. so i have 14 in my hand now, By some logic i need to get the values which are helped to get 14 Example: 2+4+8 = 14 14(some logic) = 2,4,8. 回答1: This is an easy one: 2+4+8=14 ... 14+2=16 2+4+8+16=30 ... 30+2=32 2+4+8+16+32=62 ... 62+2=64 So you just need to add 2 to your sum

方法重载参数返回值 out int.TryParse

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什么叫方法重载： 1）一般在同一个类中方法名相同，并且方法的参数个数不同，或者对应位置上的类型不同，才能构成方法的重载 2）方法重载和返回值没有关系参数返回值：例如： static void Main(string[] args) { int number; int result = Test(out number); Console.WriteLine("number={0} result={1}",number,result); Console.ReadKey(); } public static int Test(out int a) { a = 20; return a; 如上代码实现步凑： 1）在方法的参数类型前面加out，那么传参数的时候，也必须在number前加加out.表明这个参数不是传入的，而是用业传出值的. 2）如果参数是以out形式传入的，那么在传入前可以不赋初值 3）在方法中对于由 out修饰的参数，必须在使用前赋值， int.TryParse string s = "123"; int re; { if (int.TryParse(s, out re) == true) { Console.WriteLine("转换成功"); } else { Console.WriteLine("转换失败"); } } Console.ReadKey();

What is the cause? operators or use of strings? [duplicate]

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问题 This question already has answers here : Why is string “11” less than string “3”? [duplicate] (6 answers) Closed last month . Why does this happen with strings in javascript? 3<=255 true but '3'<='255' false Is it something to do with the operators or the use of strings? 回答1: I guess it is because it compare ascii values of chars and 3 had greater ascii value than 2. In string it compare char by char if 1 char is false it wont compare else 回答2: In first case you are comparing 2 Numbers, in

Get only digits from input and call that number Android

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问题 Okay, I am creating an android app, I do like to get the number from an input here mostLikelyThingHeard unfortenately my code doesn't work for some reason. For example when the user says: bel 0612345678 The dialer has to call 0612345678 String one = "bel"; if (mostLikelyThingHeard.contains(one)) { String numbers = mostLikelyThingHeard.replaceAll("[^0-9]", ""); Intent call = new Intent(Intent.ACTION_DIAL); call.setData(Uri.parse("tel:" + numbers)); tts.speak(numbers + " wordt gebeld.",