while-loop

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: C/C++: is GOTO faster than WHILE and FOR? I know this has been asked for many times, but I never got an answer which satisfies me by googling. I read somewhere that every loop(for/while/do-while/untill) will be eventually be converted to goto statements internally, Is that True? If not, Which is the best loop to use as per the performance wise? Let me know if anybody knows? 回答1: They say "converted to goto

问题 I know this might be a bit of a 'silly' question, but sometimes, I just want to loop until a condition is false but I don't like keeping the loop empty. So instead of : Visible = true; while(IsRunning) { } Visible = false; I usually prefer : while(IsRunning) { Visible = true; } Visible = false; However, I'm a bit concerned about what exactly happens at the line Visible = true; . Does the Runtime keep executing that statement even though it's redundant ? Is it even advisable to do it this way?

问题 So I posted a question before, but it was too simplified and rightly got flagged as a duplicate. I'm now posting my problem in more detail so my issue might, hopefully, be resolved. Briefly it is as follows: I have two lists: a = [10.0,20.0,25.0,40.0] and b = [1.0,10.0,15.0,20.0,30.0,100.0] Using list comprehension, I want to exclude from b the ranges of elements specified in a. That is: remove from b all elements between 10.0 and 20.0, and between 25.0 and 40.0. Here is what I tried: kk = 0

问题 So I posted a question before, but it was too simplified and rightly got flagged as a duplicate. I'm now posting my problem in more detail so my issue might, hopefully, be resolved. Briefly it is as follows: I have two lists: a = [10.0,20.0,25.0,40.0] and b = [1.0,10.0,15.0,20.0,30.0,100.0] Using list comprehension, I want to exclude from b the ranges of elements specified in a. That is: remove from b all elements between 10.0 and 20.0, and between 25.0 and 40.0. Here is what I tried: kk = 0

问题 I tried to use while_loop in Tensorflow , but when I try to return the target output from callable in while loop, it gives me an error because the shape is increased every time. The output should be contains (0 or 1) values based on data value (input array). If data value is large than 5 return 1 else return 0 . The returned value must be added into output This is the code:: import numpy as np import tensorflow as tf data = np.random.randint(10, size=(30)) data = tf.constant(data, dtype= tf

问题 We are trying to make a python program to simulate games of craps and display the probability of winning. I have narrowed down the answer to the while loop and as the title suggests, when it hits the loop it won't exit. As far as I can tell the loop should exit but instead just returns and endless train of "false". Here is the code for the whole program with comments, I'll type out the rules for craps (as far as what we're using for our program) at the bottom. import random def craps() roll =

问题 Here is the question I am working on : You want to know your grade in Computer Science, so write a program that continuously takes grades between 0 and 100 to standard input until you input "stop" , at which point it should print your average to standard output. Here is my code thus far in Python 3: total = 0 q = 1 score = input("Enter a score:") while score != "stop": q += 1 total = total + int(score) avg = total / q print(avg) I am very new at coding, and could use some help to point me in

问题 I have a while loop that outputs a list of classes. In the classes database the teacher name is determined by the teachers ID in the users database. Here is my database structure. Classes Database ----------------------------- ID CLASS TEACHER 1 product design 3 User Database ----------------------------- ID NAME 3 John Doe So when listing my classes I need it to convert "3" into "John Doe". This is my current code: <?php $classdetails = mysql_query("SELECT * FROM class"); while($class =

问题 I am using a buffered reader to read in a file filled with lines of information. Some of the longer lines of text extend to be more than one line so the buffered views them as a new line. Each line ends with ';' symbol. So I was wondering if there was a way to make the buffered reader read a line until it reaches the ';' then return the whole line as a string. Here a how I am using the buffered reader so far. String currentLine; while((currentLine = reader.readLine()) != null) { // trim

问题 I'm trying to write a function that takes a string s as an input and returns a list of those substrings within s that are alphabetical. For example, s = 'acegibdh' should return ['acegi', 'bdh'] . Here's the code I've come up with: s = 'acegibdh' ans = [] subs = [] i = 0 while i != len(s) - 1: while s[i] < s[i+1]: subs.append(s[i]) i += 1 if s[i] > s[i-1]: subs.append(s[i]) i += 1 subs = ''.join(subs) ans.append(subs) subs = [] print ans It keeps having trouble with the last letter of the