给定一个数字,任务是编写一个递归函数,以检查给定的数字是否是回文。
例子:
Input : 121
Output : yes
Input : 532
Output : no
编写函数的方法是递归调用函数,直到从背面完全遍历数字为止。使用临时变量根据在此帖子中获得的公式存储数字的倒数。在参数中传递temp变量,一旦实现n == 0的基本情况,则返回temp,该temp存储数字的倒数。
下面是上述方法的实现:
C++
// Recursive C++ program to check if the
// number is palindrome or not
#include
using namespace std;
// recursive function that returns the reverse of digits
int rev(int n, int temp)
{
// base case
if (n == 0)
return temp;
// stores the reverse of a number
temp = (temp * 10) + (n % 10);
return rev(n / 10, temp);
}
// Driver Code
int main()
{
int n = 121;
int temp = rev(n, 0);
if (temp == n)
cout << "yes" << endl;
else
cout << "no" << endl;
return 0;
}
Java
// Recursive Java program to
// check if the number is
// palindrome or not
import java.io.*;
class GFG
{
// recursive function that
// returns the reverse of digits
static int rev(int n, int temp)
{
// base case
if (n == 0)
return temp;
// stores the reverse
// of a number
temp = (temp * 10) + (n % 10);
return rev(n / 10, temp);
}
// Driver Code
public static void main (String[] args)
{
int n = 121;
int temp = rev(n, 0);
if (temp == n)
System.out.println("yes");
else
System.out.println("no" );
}
}
// This code is contributed by anuj_67.
Python3
# Recursive Python3 program to check
# if the number is palindrome or not
# Recursive function that returns
# the reverse of digits
def rev(n, temp):
# base case
if (n == 0):
return temp;
# stores the reverse of a number
temp = (temp * 10) + (n % 10);
return rev(n / 10, temp);
# Driver Code
n = 121;
temp = rev(n, 0);
if (temp != n):
print("yes");
else:
print("no");
# This code is contributed
# by mits
C#
// Recursive C# program to
// check if the number is
// palindrome or not
using System;
class GFG
{
// recursive function
// that returns the
// reverse of digits
static int rev(int n,
int temp)
{
// base case
if (n == 0)
return temp;
// stores the reverse
// of a number
temp = (temp * 10) +
(n % 10);
return rev(n / 10, temp);
}
// Driver Code
public static void Main ()
{
int n = 121;
int temp = rev(n, 0);
if (temp == n)
Console.WriteLine("yes");
else
Console.WriteLine("no" );
}
}
// This code is contributed
// by anuj_67.
PHP
Javascript
输出:
yes