变量a的数据和b的数据进行交换

用第三方变量

#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main()
{
	int a = 3;
	int b = 4;
	int tmp = 0;
	printf("交换前a= %d\n",a);
	printf("交换前b= %d\n",b);
	tmp = a;
	a = b;
	b = tmp;
	printf("交换后a= %d\n", a);
	printf("交换后b= %d\n", b);
	return 0;
}

不用第三方变量

#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main()
{
	int a = 3;//0011
	int b = 4;//0100
	printf("交换前\n");
	printf("a=%d\n", a);
	printf("b=%d\n", b);
	a = a ^ b;//0111
	b = a ^ b;//0011==3
	a = a ^ b;//0100==4
	printf("交换后\n");
	printf("a=%d\n",a);
	printf("b=%d\n",b);
	return 0;
}