# include & ltmath.h & gt
void f 1();
void F2();
void F3();
void F4();
int a,b,c,d;
void main()
{
printf("輸入a,b,c:\ n ");
scanf("%d%d%d ",& amp壹,& ampb & amp;c);
d = b * b-4 * a * c;
如果(a!=0)
{
if(d & gt;=0)
{
if(d & gt;0)f 1();
else F2();
}
else F3();
}
else F4();
}
void f1()
{
浮點x1,x2;
x 1 =(float)(-b-sqrt(d))/(2 * a);
x2 =(float)(-b+sqrt(d))/(2 * a);
Printf("方程有兩個不相等的實根。\ n ");
printf(" x1 = % . 3f \ nx2 = % . 3f \ n ",x 1,x2);
}
void f2()
{
浮動x;
x =(float)(-b)/(2 * a);
Printf("方程有兩個相等的實根。\ n ");
printf(" x 1 = % . 3f \ nx2 = % . 3f \ n ",x,x);
}
無效f3()
{
浮點x1,x2;
x 1 =(float)(-b)/(2 * a);
x2 =(float)sqrt(-d);
Printf("方程有兩個復數根。\ n ");
printf("x1=%.3f-%.3fi\n ",x1,x2);
printf("x2=%.3f+%.3fi\n ",x1,x2);
}
void f4()
{
Printf("因為a=0,所以方程不是二元線性方程。\ n ");
}