一元二次方程与一元二次函数

My_A

做了个计算 一元二次方程和一元二次函数顶点与顶点式 的程序，希望大家多多指教

#include <stdio.h>
#include <math.h>

#define NOT_ZERO(x) if((x)==0.0){return 0;}                // 二次方程的二次项系数不为0
#define SQUARE(x) ((x)*(x))
#define ANSWER(a,b,c,x) ((a)*SQUARE(x) + (b)*(x) + (c))    // 算方程结果
#define MAX_Y(a,b) ((-(b))/(2*(a)))                        // 算最大/最小值

typedef  struct{ double x,y; } POINT,*pPOINT;

typedef struct{ double x1,x2; } ANSWER_X,*pANSWER_X;

typedef struct{ double a,h,k; } VERTEX_TYPE,*pVERTEX_TYPE;

// 解方程
int solute(double a,double b,double c,pANSWER_X answer)
{
    NOT_ZERO(a);

    double delta = SQUARE(b)-(4*a*c);

    // 判断根的情况
    if(delta >= 0.0){
        if(delta > 0){
            answer->x1 = (-b+sqrt(delta))/(2*a);
            answer->x2 = (-b-sqrt(delta))/(2*a);
        }else {
            answer->x1 = answer->x2 = MAX_Y(a,b);
        }

        return 1;
    }else{
        return 0;        // 无实数根
    }
}

// 计算顶点坐标
int vertex(double a,double b,double c,pPOINT answer)
{
    NOT_ZERO(a);

    answer->x = MAX_Y(a,b);
    answer->y = ANSWER(a,b,c,answer->x);

    return 1;
}

// 计算顶点式
int vertex_type(double a,double b,double c,pVERTEX_TYPE ver){
    NOT_ZERO(a);

    double a1,h1,k1;
    POINT p1;

    vertex(a,b,c,&p1);
    h1 = p1.x;
    k1 = ANSWER(a,b,c,h1);
    a1 = (ANSWER(a,b,c,0) - k1)/(SQUARE(h1));

    ver->a = a1;
    ver->k = k1;
    ver->h = h1;

    return 1;
}

int main()
{
    // 输入一元二次方程的一般式系数
    double a=1;
    double b=-4;
    double c=3;

    ANSWER_X answer;
    POINT point;
    VERTEX_TYPE ver;

    if(solute(a,b,c,&answer)){
        printf("The quadratic answer is :\n");
        printf("\tx1 = %.3lf\n\tx2 = %.3lf\n",answer.x1,answer.x2);
    }

    if(vertex(a,b,c,&point)){
        printf("The vertex-point is :\n");
        printf("\t( %.3lf , %.3lf )\n",point.x,point.y);
    }

    if(vertex_type(a,b,c,&ver)){
        printf("The vertex-type is :\n");
        printf("\ty = %.3lf * (x - (%.3lf))^2 + (%.3lf)\n",ver.a,ver.h,ver.k);
    }


    return 0;
}