Question 1
Predict the output of following program. What does the following fun() do in general?
C++
#include <iostream>
using namespace std;
int fun( int a, int b)
{
if (b == 0)
return 0;
if (b % 2 == 0)
return fun(a + a, b/2);
return fun(a + a, b/2) + a;
}
int main()
{
cout << fun(4, 3) ;
return 0;
}
|
C
#include<stdio.h>
int fun( int a, int b)
{
if (b == 0)
return 0;
if (b % 2 == 0)
return fun(a+a, b/2);
return fun(a+a, b/2) + a;
}
int main()
{
printf ( "%d" , fun(4, 3));
getchar ();
return 0;
}
|
Java
import java.io.*;
class GFG {
static int fun( int a, int b)
{
if (b == 0 )
return 0 ;
if (b % 2 == 0 )
return fun(a + a, b/ 2 );
return fun(a + a, b/ 2 ) + a;
}
public static void main (String[] args)
{
System.out.println(fun( 4 , 3 ));
}
}
|
Python3
def fun(a, b):
if (b = = 0 ):
return 0
if (b % 2 = = 0 ):
return fun(a + a, b / / 2 )
return fun(a + a, b / / 2 ) + a
print (fun( 4 , 3 ))
|
C#
using System;
class GFG{
static int fun( int a, int b)
{
if (b == 0)
return 0;
if (b % 2 == 0)
return fun(a + a, b/2);
return fun(a + a, b/2) + a;
}
static public void Main ()
{
Console.Write(fun(4, 3));
}
}
|
It calulates a*b (a multipied b).
Question 2
In question 1, if we replace + with * and replace return 0 with return 1, then what does the changed function do? Following is the changed function.
C++
#include <iostream>
using namespace std;
int fun( int a, int b)
{
if (b == 0)
return 1;
if (b % 2 == 0)
return fun(a*a, b/2);
return fun(a*a, b/2)*a;
}
int main()
{
cout << fun(4, 3) ;
getchar ();
return 0;
}
|
C
#include<stdio.h>
int fun( int a, int b)
{
if (b == 0)
return 1;
if (b % 2 == 0)
return fun(a*a, b/2);
return fun(a*a, b/2)*a;
}
int main()
{
printf ( "%d" , fun(4, 3));
getchar ();
return 0;
}
|
Java
import java.io.*;
class GFG {
static int fun( int a, int b)
{
if (b == 0 )
return 1 ;
if (b % 2 == 0 )
return fun(a*a, b/ 2 );
return fun(a*a, b/ 2 )*a;
}
public static void main (String[] args)
{
System.out.println(fun( 4 , 3 ));
}
}
|
Python3
def fun(a, b):
if (b = = 0 ):
return 1
if (b % 2 = = 0 ):
return fun(a * a, b / / 2 )
return fun(a * a, b / / 2 ) * a
print (fun( 4 , 3 ))
|
C#
using System;
public class GFG{
static int fun( int a, int b)
{
if (b == 0)
return 1;
if (b % 2 == 0)
return fun(a*a, b/2);
return fun(a*a, b/2)*a;
}
static public void Main ()
{
Console.WriteLine(fun(4, 3));
}
}
|
It calculates a^b (a raised to power b).
Question 3
Predict the output of following program. What does the following fun() do in general?
C++
#include <iostream>
using namespace std;
int fun( int n)
{
if (n > 100)
return n - 10;
return fun(fun(n+11));
}
int main()
{
cout << " " << fun(99) << " " ;
getchar ();
return 0;
}
|
C
#include<stdio.h>
int fun( int n)
{
if (n > 100)
return n - 10;
return fun(fun(n+11));
}
int main()
{
printf ( " %d " , fun(99));
getchar ();
return 0;
}
|
Java
import java.io.*;
class GFG {
static int fun( int n)
{
if (n > 100 )
return n - 10 ;
return fun(fun(n+ 11 ));
}
public static void main (String[] args) {
System.out.println( " " + fun( 99 ) + " " );
}
}
|
Python3
def fun(n):
if (n > 100 ):
return n - 10
return fun(fun(n + 11 ))
print (fun( 99 ))
|
C#
using System;
class GFG{
static int fun( int n)
{
if (n > 100)
return n - 10;
return fun(fun(n + 11));
}
static public void Main ()
{
Console.WriteLine(fun(99));
}
}
|
fun(99) = fun(fun(110)) since 99 ? 100
= fun(100) since 110 > 100
= fun(fun(111)) since 100 ? 100
= fun(101) since 111 > 100
= 91 since 101 > 100
Returned value of fun() is 91 for all integer rguments n 101. This function is known as McCarthy 91 function.
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