i write a C program to perform the functions of a calculator,
as this
#include<stdio.h>
#include<conio.h>
int sum(int,int);
int dif(int,int);
int pro(int,int);
float div(int,int);
void main()
{
 int a,b;
 char o;
 clrscr();
 printf("enter the numbers ");
 scanf("%d%d",&a,&b);
 printf("enter the...