题解 | #反序数#

#include<cstdio>
using namespace std;
int reverse(int n){
	//名为reverse的函数，有一个int参数，返回值是int类型
	int remain ;
	int reverse = 0;
	while(n > 0){
		remain = n%10;
		n = n/10;
		reverse = reverse*10 + remain;
		//当最后一次循环执行完以后，退出循环
		if(n == 0){
			break;
			}
		}
	return reverse;
	}
int main(){
	int a,b,c,d;
	for(a = 1; a <= 9; ++a){
		for(b = 0; b <= 9; ++b){
			for(c = 0; c <= 9; ++c){
				for(d = 0; d <= 9; ++d){
					int n = 1000*a+100*b+10*c+d;
						if(n*9 == reverse(n)){
						printf("%d\n",n);
						}
					}
				}
			}
	    }
	}