Question

我正在编写一个程序供用户输入a，b，c以找到二次方程式。

请帮助我以便了解我的错误。

#include < iostream>
#include < cmath>
#include < string>


using namespace std;

//////Quadratic Formula///////

int a;

int b;

int c;

float top1;

float left1;

float left2

float under3;

float under4; 



int main()

{

 ////////////////////User Input a, b, c///////////////////////

cout << "This program will allow you to input numbers for variables a, b, and c to    find the quadratic equation" << endl;

cout << "Enter a number for a: ";
cin >> a;

if (a == 0) //If user enters 0 it will quit the program and give them error message.
{
cout << "0 is not a sufficient coefficient for this program.";
cout <<"Restart now and try again." << endl;
exit(0);
}

cout << "Enter a number for b: ";
cin >> b;
cout << "Enter a number for c: ";
cin >> c;

//////////////Calculations////////////

//////////////////b add
float top1 = (b*b)- 4*a*c);

float left1 = (-b) + sqrt(top1);

float under3 =  (left1))/(2*a);

/////////////b subtract

float top1 = (pow(b,2) - 4*a*c);

float left2 = (-b) - sqrt(top1);

float under4 =  (left2))/(2*a);




cout <<"The Answer for the Quadratic equation is:";
cout << under3(a, b, c,) <<endl;   // function call


cout <<"The first Root Value = " << under3 << endl; 
cout <<"The second Root Value = " << under4 << endl;


system("pause") ;

return 0;
}



 //px = (-b + sqrt(b * b - 4 * a * c)) / (2 * a)
 //nx = (-b - sqrt(b * b - 4 * a * c)) / (2 * a)

Answer 1

我对你的a == 0错误检查提出的一个稍微不相关的建议是使用do while语句而不是让你的程序关闭。它看起来像这样：

do
{
cout << "Enter a number for a: ";
cin >> a;
    if (a==0)
    {
    cout << "Can't use 0 for a.";
    }
} while (a==0);

这使得用户无需在输入无效号码时重新启动程序。只是一个建议。

二次方程c ++

1 个答案: