c语言二分法求根的问题

Question

二分法求根
需要输入输出正确
能够正常运行，复合题目要求.二分法
求根

Answer 1

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

double f(double x) {
    return 2 * pow(x, 3) - 4 * pow(x, 2) + 3 * x - 6;
}

double bisection(double x1, double x2, double epsilon) {
    double mid;
    while ((x2 - x1) > epsilon) {
        mid = (x1 + x2) / 2;
        if (f(mid) == 0) {
            return mid;
        }
        else if (f(x1) * f(mid) < 0) {
            x2 = mid;
        }
        else {
            x1 = mid;
        }
    }
    return (x1 + x2) / 2;
}

int main() {
    double x1, x2;
    printf("请输入区间[x1,x2]：");
    scanf("%lf %lf", &x1, &x2);

    if (f(x1) * f(x2) > 0) {
        printf("noroot\n");
    }
    else {
        double root = bisection(x1, x2, 0.001);
        printf("%.3lf\n", root);
    }

    return 0;
}