C语言实现简单一元二次方程的求解

 1 #include<stdio.h>
 2 #include<math.h>
 3 int main()
 4 {
 5     while(1)
 6     {
 7         double a,b,c;
 8         double delta;
 9         double x1,x2;
10         char ch;
11         printf("请输入三个系数：
");
12         printf("a = ");
13         scanf("%lf",&a);
14         printf("b = ");
15         scanf("%lf",&b);
16         printf("c = ");
17         scanf("%lf",&c);
18         delta = b*b - 4*a*c;
19         if(delta > 0)
20         {
21             printf("该方程有两个解：
");
22             x1 = (-b + sqrt(delta))/(2.0*a);
23             x2 = (-b - sqrt(delta))/(2.0*a);
24             printf("x1 = %lf
",x1);
25             printf("x2 = %lf
",x2);
26         }
27         else if(delta == 0)
28         {
29             printf("该方程有唯一解：
");
30              x1 = (-b + sqrt(delta))/(2.0*a);
31             x2=x1;
32             printf("x1 = %lf
",x1);
33             printf("x2 = %lf
",x2);
34         }
35         else
36         {
37             printf("该方程无解！
");
38         }
39 
40         getchar();
41         printf("是否继续下组计算：（Y/N）
");
42         scanf("%c",&ch);
43         if(ch == 'N')
44             break;
45     }
46     return 0;
47 }