functions part 4

Q Write a 'c' function to calculate the factorial of the number

(i) When the function  returns the value

#include<iostream.h>

#include<conio.h>

/*function prototype*/

int factorial(int);

void main( )

{

      int num,fact;

      clrscr();

      cout<<endl<<"Enter the number :";

      cin>>num;

      fact=factorial(num); /*function call*/

      cout<<endl<<"Factorial ="<<fact;

      getch();

}

/*function defintion */

int factorial(int num)

{

      int i,fact;

      fact=1;

      for(i=1;i<=num;i++)

            fact=fact*i;

     

      return fact;

}

(ii) When the function doesnot return the value

#include<iostream.h>

#include<conio.h>

/*function prototype */

void factorial(int);

void main()

{

      int num;

      clrscr( );

      cout<<endl<<"Enter the number :";

      cin>>num;

      factorial(num); /* function call*/

      getch();

}

/* function definition */

void factorial(int num)

{

      int i,fact;

      fact=1;

      for(i=1;i<=num;i++)

            fact=fact*i;

     

      cout<<endl<<"Factorial ="<<fact;

}

Q Write a 'c++' program using function to calculate the value

      of c.

            c =     n!

                   ----------

                    r!*(n-r)!

     

#include<iostream.h>

#include<conio.h>

/*function prototype*/

int factorial(int);

void main( )

{

      int n,r,c,factn,factr,factnr;

      clrscr();

      cout<<endl<<"Enter the value of n and r:";

      cin>>n>>r;

      /*calculate the factorial of n */

      factn=factorial(n);

      /*calculate the factorial of r */

      factr=factorial(r);

      /* calculate the factorail of n-r*/

     

      factnr=factorial(n-r);

      /*calculate the value of c */

      c=factn/(factr*factnr);

      cout<<endl<<"c="<<c;

      getch();

}

/*function definition */

int factorial(int num)

{

      int fact,i;

fact=1;

      for(i=1;i<=num;i++)

            fact=fact*i;

      return fact;

}

Q Write a 'C' function to calculate the x ^ y.

      x=5 y=3 x^ y=5^3=5*5*5=125

(i) When the function returns the value

(ii) When the function does not return the value .

Solution :

#include<iostream.h>

#include<conio.h>

/*function prototype*/

int power(int,int);

void main()

{

      int x,y,result;

      clrscr();

      cout<<endl<<"Enter the value of  x and y :";

      cin>>x>>y;

      result=power(x,y); /*function call*/

      cout<<"Result =" <<result;

      getch();

}

/*function defintion*/

int power(int x,int y)

{

      int i,result;

      result=1;

      for(i=1;i<=y;i++)

            result=result*x;

      return result;

}