#include<stdio.h> int main(){ int a,b; scanf("a=%d,b=%d",&a,&b);//如果a=2,b=1 a=a+b; //a=a+b=3 b=a-b; //b=a-b=3-1=2 a=a-b; //a=a-b=3-2=1 printf("a=%d,b=%d",a,b); return 0; }