IGNOU Solved Assignments ‘C’ Programming & Data Structure

Question 1: Write a C program to create a calculator. The program will accept an arithmetic expression (assumed to be valid expression of only +, -, *, /, 1/x, and % operations) from the user. Evaluate the expression and display the results. Including the above functions, this calculate should provide the temporary buffer (memory function), to store and retrieve the temporary number values.
Note: You may include some features and function in your calculator program.

Ans:

#include<stdio.h>
#include<process.h>
#include<conio.h>
void main()
{

float a,b,r;
int n1,n2,r1;
char op;
clrscr();
while(1)
{
fflush(stdin);
printf("\n enter operator ");
scanf("%c",&op);
switch(op)
{
case'+':printf("\nenter value of a ");
scanf("%f",&a);
printf("\nenter value of b ");
scanf("%f",&b);
r=a+b;
printf("\nresult=%2f",r);
getch();
break;
case'-':printf("\nenter value of a ");
scanf("%f",&a);
printf("\nenter value of b ");
scanf("%f",&b);
r=a-b;
printf("\nresult=%2f",r);
getch();
break;
case'*':printf("\nenter value of a ");
scanf("%f",&a);
printf("\nenter value of b ");
scanf("%f",&b);
r=a*b;
printf("\nresult=%2f",r);
getch();
break;
case'/':printf("\nenter value of a ");
scanf("%f",&a);
printf("\nenter value of b ");
scanf("%f",&b);
r=a/b;
printf("\nresult=%2f",r);
getch();
break;
case'%':printf("\nenter value of n1 ");
scanf("%d",&n1);
printf("\nenter value of n2 ");
scanf("%d",&n2);
r1=n1%n2;
printf("\nresult=%2d",r1);
getch();
break;
default:printf("\nWRONG ENTRY");
getch();
exit(op);
}}}