C语言数学公式计算器：二次方程、勾股定理、三角形面积等

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

#define PI 3.1415926

tydef struct Formula { char name[100]; char content[100]; struct Formula *next; } Formula;

void quadraticEquation(); void pythagoreanTheorem(); void areaOfTriangle(); void volumeOfCylinder(); void SOfBall(); void volumeOFBall(); void daoshu(); void addNewFormula(); void deleteFormula();

Formula *head = NULL;

int main() { int a; // 第一级选择 while (1) { printf("\n"); printf("\n请选择以下几个选项\n"); printf("1.常见公式查询\n"); printf("2.部分公式计算\n"); printf("3.退出程序\n"); printf("\n"); printf("您的选项是：\n"); scanf("%d", &a);

    if (a == 3)
        return 0;
    if (a == 1 || a == 2)
        ;
    else
        printf("您输入的选项不合法！请重试\n");


while (a == 1) {
    printf("\n请在以下选项中选择您要查询的公式：\n");
    printf("1.常见函数的导数\n");
    printf("2.正弦定理\n");
    printf("3.余弦定理\n");
    printf("4.辅助角定理\n");
    printf("5.球的表面积公式\n");
    printf("6.球的体积公式\n");
    printf("7.添加新公式或查询已添加的公式\n");
    printf("0.返回上一级\n");
    int b; // 第二级选择
    scanf("%d", &b);
    switch (b) {
        case 0:
            b = 0;
            a = 0;
            break;
        case 1:
            daoshu();
            break;
        case 2:
            printf("a/sin A=b/sin B=c/sin C=2R\n");
            printf("R外三角形的外接圆半径\n");
            break;
        case 3:
            printf("cos A=b*b+c*c-a*a/2bc\n");
            break;
        case 4:
            printf("asinx+bcosx=√ (a2+b2)sin [x+arctan (b/a)]\n");
            break;
        case 5:
            printf("S=4ΠR*R\n");
            break;
        case 6:
            printf("V=4ΠR*R*R/3\n");
            break;
        case 7:
            addNewFormula();
            break;
        default:
            printf("无效的选项，请重新输入。\n");
            break;
    }
}

int choice; // 第二级选择

while (a == 2) {
    printf("\n请选择要查询的数学公式：\n");
    printf("1. 二次方程\n");
    printf("2. 勾股定理\n");
    printf("3. 三角形面积\n");
    printf("4. 圆柱体体积\n");
    printf("5.球的表面积\n");
    printf("6.球的体积\n");
    printf("0. 返回上一级\n");
    printf("请输入选项：\n");
    scanf("%d", &choice);

    switch (choice) {
        case 0:
            choice = 0;
            a = 0;
            break;
        case 1:
            quadraticEquation();
            break;
        case 2:
            pythagoreanTheorem();
            break;
        case 3:
            areaOfTriangle();
            break;
        case 4:
            volumeOfCylinder();
            break;
        case 5:
            SOfBall();
            break;
        case 6:
            volumeOFBall();
            break;
        default:
            printf("无效的选项，请重新输入。\n");
            break;
    }
}

} return 0; }

// 二次方程函数 void quadraticEquation() { double a, b, c; double discriminant; double root1, root2;

printf("\n请输入二次方程的系数：\n");
printf("a = ");
scanf("%lf", &a);
printf("b = ");
scanf("%lf", &b);
printf("c = ");
scanf("%lf", &c);

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

if (discriminant > 0) {
    root1 = (-b + sqrt(discriminant)) / (2 * a);
    root2 = (-b - sqrt(discriminant)) / (2 * a);
    printf("方程的两个根为：%.2lf和%.2lf\n", root1, root2);
} else if (discriminant == 0) {
    root1 = -b / (2 * a);
    printf("方程的两个根相等，为：%.2lf\n", root1);
} else {
    double realPart = -b / (2 * a);
    double imaginaryPart = sqrt(-discriminant) / (2 * a);
    printf("方程的两个复根为：%.2lf + %.2lfi和%.2lf - %.2lfi\n", realPart, imaginaryPart, realPart, imaginaryPart);
}

}

// 勾股定理函数 void pythagoreanTheorem() { double a, b, c;

printf("\n请输入三角形的两条直角边的长度：\n");
printf("a = ");
scanf("%lf", &a);
printf("b = ");
scanf("%lf", &b);

c = sqrt(a * a + b * b);
printf("斜边的长度为：%.2lf\n", c);

}

// 三角形的面积计算函数 void areaOfTriangle() { double base, height;

printf("\n请输入三角形的底和高：\n");
printf("底 = ");
scanf("%lf", &base);
printf("高 = ");
scanf("%lf", &height);

double area = 0.5 * base * height;
printf("三角形的面积为：%.2lf\n", area);

}

// 圆柱体体积函数 void volumeOfCylinder() { double radius, height;

printf("\n请输入圆柱体的底面半径和高：\n");
printf("半径 = ");
scanf("%lf", &radius);
printf("高 = ");
scanf("%lf", &height);

double volume = PI * radius * radius * height;
printf("圆柱体的体积为：%.2lf\n", volume);

}

// 球的表面积函数 void SOfBall() { printf("请输入球的半径：\n"); int r; double S; scanf("%d", &r); S = 4 * PI * r * r; printf("球的表面积为：%.21f\n", S); }

// 球的体积函数 void volumeOFBall() { printf("请输入球的半径：\n"); int r; double V; scanf("%d", &r); V = 4 * PI * r * r * r / 3; printf("球的表面积为：%.21f\n", V); }

// 常见导数的函数 void daoshu() { printf("(C) ′=0, C为常数\n"); printf("x ′=1\n"); printf("(In x) ′=1/x\n"); printf("sin x ′=cos x\n"); printf("cos x ′=(-sin x)\n"); }

// 添加新公式函数 void addNewFormula() { printf("您已添加的公式有：\n"); Formula *current = head; int count = 1; while (current != NULL) { printf("%d. %s: %s\n", count, current->name, current->content); current = current->next; count++; }

printf("1.添加新公式\n");
printf("2.删除已添加公式\n");
printf("3.退出\n");
int x;
scanf("%d", &x);
if (x == 3) {
    return;
} else if (x == 1) {
    Formula *newFormula = (Formula *)malloc(sizeof(Formula));
    if (newFormula == NULL) {
        printf("内存分配失败！\n");
        return;
    }
    printf("请输入要添加的公式名称：\n");
    scanf("%s", newFormula->name);

    printf("请输入公式的内容：\n");
    scanf("%s", newFormula->content);

    newFormula->next = head;
    head = newFormula;
    printf("公式已成功添加！\n");
} else if (x == 2) {
    deleteFormula();
} else {
    printf("您输入的选项不合法，请重试\n");
}

}

// 删除已添加公式函数 void deleteFormula() { printf("您已添加的公式有：\n"); Formula *current = head; int count = 1; while (current != NULL) { printf("%d. %s: %s\n", count, current->name, current->content); current = current->next; count++; }

printf("请输入要删除的公式序号：\n");
int deleteNum;
scanf("%d", &deleteNum);

if (deleteNum < 1 || deleteNum > count) {
    printf("无效的序号，请重新输入。\n");
    return;
}

Formula *prev = NULL;
current = head;
int i = 1;
while (current != NULL && i < deleteNum) {
    prev = current;
    current = current->next;
    i++;
}

if (current == NULL) {
    printf("没有找到要删除的公式。\n");
    return;
}

if (prev == NULL) {
    head = current->next;
} else {
    prev->next = current->next;
}
free(current);
printf("公式已成功删除！\n");

}