变量交换的三种方式

#include<stdio.h>
int main(){
int a,b;
scanf("%d%d",&a,&b);
printf("%d %d\n",a,b);
a=a+b;
b=a-b;
a=a-b;
printf("%d %d\n",a,b);
return 0;
}
#include<stdio.h>
int main(){
int a,b;
scanf("%d%d",&a,&b);
printf("%d %d\n",a,b);
a^=b;
b^=a;
a^=b;
printf("%d %d\n",a,b);
return 0;
}

#include<stdio.h>
int main(){
int a,b;
scanf("%d%d",&a,&b);
printf("%d %d\n",a,b);
int t;
t=a;
a=b;
b=t;
printf("%d %d\n",a,b);
return 0;
}