this is a simple calculator program and it is obvious that this program will calculate the number entered by user.The main key of this program is switch case statement. due to switch case the program can can decide that which option is selected and program will work as per user's choice.
Program:
#include<stdio.h>
#include<conio.h>
#include<math.h>
#define H 100
void main()
{
int number1,number2,result;
float outof,total,result2;
char wish;
clrscr();
printf("\nA: addition");
printf("\nS: substraction");
printf("\nM: multiplication");
printf("\nD: division");
printf("\nP: percentage");
printf("\nchoice: ");
wish=getchar();
switch(wish)
{
case'S':printf("\n\nnumber1: ");
scanf("%d",&number1);
printf("\nnumber2: ");
scanf("%d",&number2);
result=number1-number2;
printf("\nyour answer is %d",result);
break;
case'M':printf("\nnumber1: ");
scanf("%d",&number1);
printf("\nnumber2: ");
scanf("%d",&number2);
result=number1*number2;
printf("your answer is %d",result);
break;
case'D':printf("\nnumber1: ");
scanf("%d",&number1);
printf("\nnumber2: ");
scanf("%d",&number2);
result=number1/number2;
printf("your answer is %d",result);
break;
case'A':printf("\nnumber1: ");
scanf("%d",&number1);
printf("\nnumber2: ");
scanf("%d",&number2);
result=number1+number2;
printf("your answer is %d",result);
break;
case's':printf("\n\nnumber1: ");
scanf("%d",&number1);
printf("\nnumber2: ");
scanf("%d",&number2);
result=number1-number2;
printf("your answer is %d",result);
break;
case'm':printf("\nnumber1: ");
scanf("%d",&number1);
printf("\nnumber2: ");
scanf("%d",&number2);
result=number1*number2;
printf("your answer is %d",result);
break;
case'd':printf("\nnumber1: ");
scanf("%d",&number1);
printf("\nnumber2: ");
scanf("%d",&number2);
result=number1/number2;
printf("your answer is %d",result);
break;
case'a':printf("\nnumber1: ");
scanf("%d",&number1);
printf("\nnumber2: ");
scanf("%d",&number2);
result=number1+number2;
printf("your answer is %d",result);
break;
case'P':printf("\n total: ");
scanf("%f",&total);
printf("\n earned: ");
scanf("%f",&outof);
result2=outof*100/total;
printf("your answer is %f%",result2);
break;
case'p':printf("\n total: ");
scanf("%f",&total);
printf("\n earned: ");
scanf("%f",&outof);
result2=outof*100/total;
printf("your answer is %f%",result2);
break;
default:printf("You have entered wrong choice");
break;
}
printf("\npress any key to close program");
getch();
}