[编程入门]自定义函数求一元二次方程-题解（C语言代码）

解题思路:一定要看题目的输出格式

注意事项:

参考代码:

#include <stdlib.h>

#include<stdio.h>

#include <math.h>

void smaller(float a, float b, float d);

void mid(float a, float b, float d);

void bigger(float a, float b, float d);

int main()

{

float a, b, c, d;

void(*p)(float x, float y ,float z);

scanf("%f%f%f", &a, &b, &c);

d = b * b - 4 * a * c;

if (d < 0)

{

p = smaller;

}

else if (d == 0)

{

p = mid;

}

else

{

p = bigger;

}

p(a , b , d);

}

void smaller(float a, float b, float d)

{

printf("x1=%.3f+%.3fi ", -b / a / 2,sqrt(-d)/2/a );

printf("x2=%.3f-%.3fi", -b / a / 2, sqrt(-d)/2/a);

}

void mid(float a, float b, float d)

{

printf("x1=%.3f", -b / a / 2);

printf("x2=%.3f", -b / a / 2);

}

void bigger(float a, float b, float d)

{

printf("x1=%.3f  ",- b / a / 2 + sqrt(d)/a/2);

printf("x2=%.3f ", -b / a / 2 -  sqrt(d) / a / 2);

}