#include<iostream.h>//一元二次方程
#include<math.h>
void wujie();
void yijie(double a,double b,double c);
void liangjie(double a,double b,double c);
void main()
{double a,b,c,d;
cout<<"请依次输入a,b,c"<<endl;
cin>>a>>b>>c;
 d=b*b-4*a*c;
 if(d<0)
 {void wujie();
 }
   if(d=0)
   {void yijie(double a,double b,double c);
   }
   else
   void liangjie(double a,double b,double c);
   
}

 void wujie()
 {   
    cout<<"方程无解"<<endl;   
   
 }
 void yijie(double a,double b,double c)
 {
 double x1,d;
 {d=b*b-4*a*c;
    x1=(-1*b)/(2*a);
cout<<"该方程只有一解"<<"x="<<x1<<endl;
   
 }   
 void liangjie(double a,double b,double c)
 {double d,x1,x2;
     d=b*b-4*a*c;
    x1=(-1*b+sqrt(d))/(2*a);
    x2=(-1*b-sqrt(d))/(2*a);
cout<<"该方程有两解"<<"x1="<<x1<<" "<<"x2="<<x2<<endl;   
 }


报错error C2601: 'liangjie' : local function definitions are illegal
报错fatal error C1004: unexpected end of file found

自己将代码排版一下就能发现问题了

你之所以看不出问题，是因为你的代码太乱
别人要想发现的问题，也得先将你的代码排列整齐才能发现
而将代码排序整型这种活，你自己可以干，如果你自己干了，自己就能发现问题，不需要问别人。

#include<iostream>//一元二次方程
#include<math.h>
using namespace std;
void wujie();
void yijie(double a,double b,double c);
void liangjie(double a,double b,double c);
static double d;
int main()
{
    double a;
    double b;
    double c;

    cout<<"请依次输入a,b,c"<<endl;
    cin>>a>>b>>c;

    d=b*b-4*a*c;

    if(d<0)
    {
        wujie();
    }
    else if(d==0)
    {
        yijie(a,b,c);
    }
    else
    {
        liangjie(a,b,c);
    }
    return 0;

}

void wujie()
{
    cout<<"方程无解"<<endl;

}
void yijie(double a,double b,double c)
{
    double x;

    x=(-1*b)/(2*a);
    cout<<"该方程只有一解"<<"x="<<x<<endl;

}
void liangjie(double a,double b,double c)
{
    double x1;
    double x2;
    x1=(-1*b+sqrt(d))/(2*a);
    x2=(-1*b-sqrt(d))/(2*a);
    cout<<"该方程有两解"<<"x1="<<x1<<" "<<"x2="<<x2<<endl;
}
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