如果我们反转数字，它也保持不变，该数字也称为回文数。例如，12321 是回文数，因为如果我们反转它的数字它仍然是相同的。在本文中，我们共享了两个 C 程序来检查输入数字是否为回文数。 1）使用while循环 2）使用递归。
程序 1：使用while循环检查回文
/* Program to check if a number is palindrome or not * using while loop */#include <stdio.h>int main(){ int num, reverse_num=0, remainder,temp; printf("Enter an integer: "); scanf("%d", &num); /* Here we are generating a new number (reverse_num) * by reversing the digits of original input number */ temp=num; while(temp!=0) { remainder=temp%10; reverse_num=reverse_num*10+remainder; temp/=10; } /* If the original input number (num) is equal to * to its reverse (reverse_num) then its palindrome * else it is not. */ if(reverse_num==num) printf("%d is a palindrome number",num); else printf("%d is not a palindrome number",num); return 0;}输出：
程序 2：使用递归检查回文
#include<stdio.h>int check_palindrome(int num){ static int reverse_num=0,rem; if(num!=0){ rem=num%10; reverse_num=reverse_num*10+rem; check_palindrome(num/10); } return reverse_num;}int main(){ int num, reverse_num; printf("Enter a number: "); scanf("%d",&num); reverse_num = check_palindrome(num); if(num==reverse_num) printf("%d is a palindrome number",num); else printf("%d is not a palindrome number",num); return 0;}输出：
