我检查阿姆斯特朗号码的程序显示153为非阿姆斯特朗号码。请检查一下。我使用代码块作为编译器 [英] My program to check for armstrong number is showing 153 as non armstrong number. Please check it out. I am using code block as complier
问题描述
#include< iostream>
#include< cmath>
使用命名空间std;
int main（）
{
int n1，r，n2，p，i;
n2 = i = 0;
cout<<输入no.\;
cin>> n1;
p = n1;
while（p！= 0）
{
p = p / 10;
i ++;
}
p = n1 ;
while（p！= 0）
{
r = p％10;
p = p / 10 ;
n2 = n2 + pow（r，i）;
}
if（n1 == n2）
cout<< n1<<是一个非常强的号码\ n;
其他
cout<< n1<<不是一个武器号码\ n;
}
我的尝试：
当变量n1 = 153然后while循环的第二次迭代显示变量n2的错误值它应该是27 + 125 = 152但不是这样它是s嚎叫27 + 124 = 151。因此，在最终输出时，它显示153为非阿姆斯特朗号。请检查这个问题并发送反馈给我。
谢谢你
#include<iostream>
#include<cmath>
using namespace std;
int main()
{
int n1,r,n2,p,i;
n2=i=0;
cout<<"enter the no.\n";
cin>>n1;
p=n1;
while(p!=0)
{
p=p/10;
i++;
}
p=n1;
while(p!=0)
{
r=p%10;
p=p/10;
n2=n2+pow(r,i);
}
if(n1==n2)
cout<<n1<<" is an armstrong number\n";
else
cout<<n1<<" is not an armstrong number\n";
}
What I have tried:
when variable n1=153 then the 2nd iteration of while loop is showing wrong value of variable n2 it should be 27+125=152 but instead of this it is showing 27+124=151. Hence at final output it shows 153 as non armstrong number. PLEASE CHECK THIS PROBLEM AND SEND FEEDBACK TO ME.
THANK YOU
推荐答案
My检查阿姆斯特朗号的程序显示153为非阿姆斯特朗号。
My program to check for armstrong number is showing 153 as non armstrong number.
你的问题是你混合浮点函数和整数运算。
考虑比整数的浮点值永远不会精确，因此你的问题。
pow（）是double。
Your problem is that you mix floating point functions and integer arithmetic.
Consider than the floating point value of an integer is never exact, thus your problem.
pow() is double.
编译并不意味着你的代码是正确的！ ：笑：
将开发过程想象成编写电子邮件：成功编译意味着您使用正确的语言编写电子邮件 - 例如英语而不是德语 - 而不是电子邮件包含您的邮件想发送。
所以现在你进入第二阶段的发展（实际上它是第四或第五阶段，但你将在之后的阶段进入）：测试和调试。
首先查看它的作用，以及它与你想要的有何不同。这很重要，因为它可以为您提供有关其原因的信息。例如，如果程序旨在让用户输入一个数字并将其翻倍并打印答案，那么如果输入/输出是这样的：
Compiling does not mean your code is right! :laugh:
Think of the development process as writing an email: compiling successfully means that you wrote the email in the right language - English, rather than German for example - not that the email contained the message you wanted to send.
So now you enter the second stage of development (in reality it's the fourth or fifth, but you'll come to the earlier stages later): Testing and Debugging.
Start by looking at what it does do, and how that differs from what you wanted. This is important, because it give you information as to why it's doing it. For example, if a program is intended to let the user enter a number and it doubles it and prints the answer, then if the input / output was like this:
Input Expected output Actual output
1 2 1
2 4 4
3 6 9
4 8 16然后很明显问题出在将它加倍的位 - 它不会将自身加到自身上，或者将它乘以2，它会将它自身相乘并返回输入的平方。
所以，你可以查看代码和很明显，它在某处：
Then it's fairly obvious that the problem is with the bit which doubles it - it's not adding itself to itself, or multiplying it by 2, it's multiplying it by itself and returning the square of the input.
So with that, you can look at the code and it's obvious that it's somewhere here:
int Double(int value)
{
return value * value;
}
一旦你知道可能出现的问题，就开始使用调试器找出原因。在方法的第一行放置一个断点，然后运行你的应用程序。当它到达断点时，调试器将停止，并将控制权移交给您。您现在可以逐行运行代码（称为单步执行）并根据需要查看（甚至更改）变量内容（哎呀，您甚至可以更改代码并在需要时再试一次）。 />
在执行代码之前，请考虑代码中的每一行应该做什么，并将其与使用Step over按钮依次执行每一行时实际执行的操作进行比较。它符合您的期望吗？如果是这样，请转到下一行。
如果没有，为什么不呢？它有什么不同？
希望这可以帮助你找到代码的哪个部分有问题，以及问题是什么。
这是一项技能，它是一个值得开发的，因为它可以帮助你在现实世界和发展中。和所有技能一样，它只能通过使用来改进！
Once you have an idea what might be going wrong, start using the debugger to find out why. Put a breakpoint on the first line of the method, and run your app. When it reaches the breakpoint, the debugger will stop, and hand control over to you. You can now run your code line-by-line (called "single stepping") and look at (or even change) variable contents as necessary (heck, you can even change the code and try again if you need to).
Think about what each line in the code should do before you execute it, and compare that to what it actually did when you use the "Step over" button to execute each line in turn. Did it do what you expect? If so, move on to the next line.
If not, why not? How does it differ?
Hopefully, that should help you locate which part of that code has a problem, and what the problem is.
This is a skill, and it's one which is well worth developing as it helps you in the real world as well as in development. And like all skills, it only improves by use!
在main方法的开头放置一个断点，在调试模式下启动解决方案，然后开始观察算法不同的地方从你的期望来看。
如果你确实需要调试帮助，它是什么以及如何完成，那么我们可以提供适当的信息源。调试对于开发人员来说不是可选的，对于任何想要认真对待开发的人来说，调试是必须的。
Put a breakpoint at the beginning of the main method, launch your solution in debug mode, and start watching for the place where your algorithm differs from what you expect.
If you do need help with debugging, what it is for and how it is done, then we can provide appropriate information sources. Debugging is not optional for a developper, it is a must-know for anyone who wants to be serious about development.
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