计算方法之二分法求方程根

/************************
* 用二分法求方程
* f(x)=x^3-2x-5=0
* 在区间[2,3]内的根
*************************/
#include<stdio.h>
#include<math.h>
#include<conio.h>

float f(float x) {
	float a;
	a = x * x * x - 2 * x - 5;
	return a;
}
int main() {
	float a, b, e, x;
	printf("\nplease input data a = ");
	scanf("%f", &a);
	printf("\nplease input data b = ");
	scanf("%f", &b);
	printf("\nplease input data eps = ");
	scanf("%f", &e);
	if (f(a) * f(b) < 0) {
		while (f(x) != 0) {
			x = (a + b) / 2;
			if (f(a) * f(x) < 0) {
				b = x;
				if (abs(b - a) < e) {
					break;
				} else
					continue;
			} else {
				a = x;
				if (abs(b - a) < e) {
					break;
				} else
					continue;
			}
		}
		printf("\n");
		x = (a + b) / 2;
		printf("The root of f(x) = 0 is x =\t%f\n", x);
	} else
		printf("\n Not root ! Afresh input!\n");
	return 0;
}