给定两个整形变量的值，将两个值的内容进行交换

允许创建临时变量

#include<stdio.h>
#pragma warning(disable:4996)
#include<Windows.h>
int main()
{
int a = 10;
int b = 20;
int temp;
printf("a=%d,b=%d\n", a, b);
temp = a;
a = b;
b = temp;
printf("a=%d,b=%d", a, b);
system("pause");
return 0;
}不允许创建临时变量
（1）#include<stdio.h>
#pragma warning(disable:4996)
#include<Windows.h>
int main()
{
int a = 10;
int b = 20;
printf("a=%d,b=%d\n", a, b);
a = a - b;
b = a + b;
a = b - a;
printf("a=%d,b=%d", a, b);
system("pause");
return 0;
}
（2）

#include<stdio.h>
#pragma warning(disable:4996)
#include<Windows.h>
int main()
{
int a = 10;
int b = 20;
printf("a=%d,b=%d\n", a, b);
a = a^b;
b = a^b;
a = a^b;
printf("a=%d,b=%d", a, b);
system("pause");
return 0;
}