经典算法一

一、交换a，b

#include <IOSTREAM>

using namespace std;
void main()
{
int a =2,b=4;
// a = a+b-(b=a);        //交换a，b
a=a^b;b =b^a;a=a^b;   //交换a，b
cout<<a<<" "<<b<<endl;

}

二、int转换成二进制

void bice(unsigned long n)
{
unsigned long i = n%2;
if(n/2)bice(n/2);
cout<<i;
}