Question

我正在学习C ++，我正在尝试创建一个程序来查找正整数的阶乘。我已经能够找到正整数的阶乘。但是，当输入不是正整数时，我仍然试图让程序给出错误消息。到目前为止，错误消息已与标准输出消息组合在一起。

如何构造循环，以便为正整数输入找到给定正整数的阶乘，而在输入不是正整数时仅提供错误消息？代码如下。谢谢。

#include<iostream>
#include<string>

using namespace std;

int main()

{

    int i;
    int n;
    int factorial;

    factorial = 1;

    cout << "Enter a positive integer. This application will find its factorial." << '\n';
    cin >> i;

    if (i < 1)
    {
        cout << "Please enter a positive integer" << endl;
        break;
    }

    else
        for (n = 1; n <= i; ++n)
        {
            factorial *= n;
        }

    cout << " Factorial " << i << " is " << factorial << endl;

    return 0;
}

Answer 1

我没有检查你的阶乘函数是否返回正确的结果。此外，您可能希望将其递归，:)）

为else添加大括号：

#include<iostream>
#include<string>

using namespace std;

int main()

{

    int i;
    int n;
    int factorial;

    factorial = 1;

    cout << "Enter a positive integer. This application will find its factorial." << '\n';
    cin >> i;

    if (i < 1)
    {
        cout << "Please enter a positive integer" << endl;
        break;
    }

    else {
        for (n = 1; n <= i; ++n)
        {
            factorial *= n;
        }
        cout << " Factorial " << i << " is " << factorial << endl;
    }

    return 0;
}

Answer 2

c ++有一个完整的阶乘数字程序，它处理正数，负数和零。

#include<iostream>
using namespace std;
i

nt main()
{
    int number,factorial=1;
    cout<<"Enter Number to find its Factorial: ";
    cin>>number;
    if(number<0)
    {
        cout<<"Not Defined.";
    }
    else if (number==0)
    {
        cout<<"The Facorial of 0 is 1.";
    }
    else
    {
      for(int i=1;i<=number;i++)
      {
          factorial=factorial*i;
      }
    cout<<"The Facorial of "<<number<<" is "<<factorial<<endl;
    }
    return 0;
}

您可以阅读http://www.cppbeginner.com/numbers/how-to-find-factorial-of-number-in-cpp/

上的完整代码说明

编程以查找数字的阶乘并为负整数输入提供错误消息

2 个答案: