一个简单的计算器（图）

#include "stdAfx.h"#include "ctype.h"#include "stdlib.h"void add();void sub();void mul();void div();int main(void){int ch;printf("Please enter your calculated\nserial number to the press CTRL + Z exit\n");printf("***************************\n");printf("a:add                 b:sub\n");printf("c:mul                 d:div\n");printf("***************************\n");while((ch=getchar())!=EOF){system("cls");switch(ch){case 'a':add();printf("NEXT?ELSE(CTRL+Z):\n");getchar();break;case 'b':sub();printf("NEXT?ELSE(CTRL+Z):\n");getchar();break;case 'c':mul();printf("NEXT? ELSE (CTRL+Z):\n");getchar();break;case 'd':div();printf("NEXT? ELSE (CTRL+Z):\n");getchar();break;default:break;}}printf("Done!\n");system("pause");return 0;}void add(){float a,b;printf("You have into the addition\n");printf("please enter the first number:\n");scanf("%f",&a);printf("Please enter the second number:\n");scanf("%f",&b);printf("%f + %f = %0.2f\n",a,b,a+b);}void sub(){float a,b;printf("You have into the subtraction\n");printf("please enter the first number:\n");scanf("%f",&a);printf("Please enter the second number:\n");scanf("%f",&b);printf("%f - %f = %0.2f\n",a,b,a-b);}void mul(){float a,b;printf("You have into the multiplication\n");printf("please enter the first number:\n");scanf("%f",&a);printf("Please enter the second number:\n");scanf("%f",&b);printf("%f * %f = %0.2f\n",a,b,a*b);}void div(){float a,b;printf("You have into the division\n");printf("please enter the first number:\n");scanf("%f",&a);printf("Please enter the second number:\n");A:scanf("%f",&b);if(b==0){printf("division second number can't input '0'\nagain:\n");goto A;}elseprintf("%f / %f = %0.2f\n",a,b,a/b);}