输入一个整数，如83721，输出其逆序数12738
#include <iostream>
using namespace std;
int reverseNumber ( int input )
{
int retval = 0;
while ( input )
{
int lowNumber = input % 10 ;
retval = retval * 10 + lowNumber;
input = (input - lowNumber)/10;
}
return retval;
}
int main()
{
cout << "Hello World!" << endl;
cout << reverseNumber(83721)<<endl;
return 0;
}