计算器的设计与实现c语言作业源码+代码详细注释.zip

#include<stdio.h> #include<math.h> #include<stdlib.h> #define pi 3.1415926 double CAL_LNX(); double CAL_SINX(); double CAL_COSX(); double Calculation(double a); double angle_to_radian(double k); double my_sin(double x); double my_cos(double x1); double My_choice(int c); int fact(int i); /*自然对数*/ double CAL_LNX() { double a;//a为指数 printf("***************欢迎使用自然对数的近似计算系统！***************\n"); printf("ln"); scan: scanf_s("%lf", &a); if (a <= 0) { printf("input error!\n"); printf("please input another number: \n"); goto scan; } printf("结果是：ln%f=%f\n",a, Calculation(a)); return 0; } /*自然函数的近似计算*/ double Calculation(double a) { int n, i; double x, y = 1, Result = 0; double FENSHU = 0; x = (double)(a - 1) / (a + 1); for (n = 1;;n++) { FENSHU = (double)1 / (2 * n + 1) * pow(pow(x, 2), n); y = y + FENSHU; /*误差分析*/ if (FENSHU < 0.000001) { Result = 2 * x * y; return Result; } } } /*sinx的计算*/ double CAL_SINX() { double a; float b; printf("***************欢迎使用正弦的近似计算系统！***************\n"); printf("sin"); scanf_s("%lf", &a); b = (float)a; a = angle_to_radian(a); printf("sin%.2f=%f\n", b, my_sin(a)); return 0; } /*sina的近似计算*/ double my_sin(double x) { double fenzi, fenmu, fore, y = 0; int n, f = 0; for (n = 1;;n += 2) { fenzi = pow(x, n); fore = pow((-1), f++); fenmu = fact(n); y = y + (double)fore * fenzi / fenmu; if ((double)fenzi / fenmu < 1e-6) break; } return y; } /*度数与弧度的转换*/ double angle_to_radian(double k) { return k / 180 * pi; } /*计算阶乘*/ int fact(int i) { if (i <= 1) return 1; else return i * fact(i - 1); } /*cosx*/ double CAL_COSX() { double a1; float b1; printf("***************欢迎使用余弦的近似计算系统！***************\n"); printf("cos"); scanf_s("%lf", &a1); b1 = (float)a1; a1 = angle_to_radian(a1); printf("cos%.2f=%f\n", b1, my_cos(a1)); return 0; } /*近似计算cosa1*/ double my_cos(double x1) { double fenzi, fenmu, fore, y = 0; int n, f = 0; for (n = 0;;n += 2) { fenzi = pow(x1, n); fore = pow((-1), f++); fenmu = fact(n); y = y + (double)fore * fenzi / fenmu; if ((double)fenzi / fenmu < 1e-6) break; } return y; } /*用户选择函数类型*/ double My_choice(int c) { switch (c) { case 0: CAL_SINX(); break; case 1:CAL_COSX(); break; case 2:CAL_LNX(); break; } return 0; } int main(void) { int my_choice, sec_choice; menu: printf(" **********欢迎使用自然对数与正余弦函数的近似计算系统！*********\n" " ** 请选择您需要计算的函数类型： **\n" " ** sinx:0 **\n" " ** cosx:1 **\n" " ** lnx:2 **\n" " ***************************************************************\n"); scanf_s("%d", &my_choice); system("cls"); My_choice(my_choice); printf("若想再次选择函数类型，请按1回到主页面\n"); scanf_s("%d", &sec_choice); system("cls"); if (sec_choice == 1) goto menu; return 0; }