Question 1
Predict the output of the 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));
}
}
|
Javascript
<script>
function fun(a, b)
{
if (b == 0)
return 0;
if (b % 2 == 0)
return fun(a + a, Math.floor(b/2));
return fun(a + a, Math.floor(b/2)) + a;
}
document.write(fun(4, 3));
</script>
|
Он вычисляет a * b (умноженное на 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));
}
}
|
Javascript
<script>
function fun(a, b)
{
if (b == 0)
return 1;
if (b % 2 == 0)
return fun(a * a, Math.floor(b/2));
return fun(a * a, Math.floor(b/2)) * a;
}
document.write(fun(4, 3));
</script>
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