C语言二分法求函数零点

Question

问题遇到的现象和发生背景

求问这些代码有什么问题吗，运行出来什么都没有

用代码块功能插入代码，请勿粘贴截图

#include <stdio.h>
#include <math.h>
double f(double y)
{
    int a=0;
    double b;
    b = a * a + a * sin(a) - 5;
          return y;
}

void main()
{
    double a=0, b=5,c;
    c = (a + b) / 2;
        for (; fabs(b - a) >= 1e-5;)
        {
            if (f(a) * f(b) < 0)
                b = c;
            else
                a = c;
        }
    printf("%lf", c);
}

运行结果及报错内容

Answer 1

void main()
{
    double a=0, b=5,c;
        for (; fabs(b - a) >= 1e-5;)
        {
            c = (a + b) / 2;
            if (f(a) * f(b) < 0)
                b = c;
            else
                a = c;
        }
    printf("%lf", c);
}