编辑代码

#include <stdio.h>
#include<math.h>
int main()
{
    double a,b,c,D,x1,x2,p,q,m;
    printf("请输入a,b,c的值\n");
    scanf("%lf%lf%lf",&a,&b,&c);
    D=b*b-4*a*c;
    if(a==0)
    printf("Eroor\n");
    else
    if(D=0)
    m=-b/(2*a);
    printf("两个相等的实根x1=x2=%f\n",m);
    else
    if(D>0)
    p=-b/(2*a);
    q=sqrt(D)/(2*a);
    x1=p+q;
    x2=p-q;
    printf("两个不等的实根x1=%7.2f\nx2=%7.2f\n",x1,x2);
    else
    p=-b/(2*a);
    q=sqrt(-D)/(2*a)
    x1=p+q;
    x2=p-q;
    printf("两个不等的虚根x1=&7.2fi\nx2=&7.2fi\n",x1,x2);
    return 0;  
}