好吧我明白了..QAQ
by ysj1173886760 @ 2018-09-17 17:58:25
异或进行swap(a,b)如果a==b就挂了
by Kniqht @ 2020-07-07 13:41:26
不保险，还是推荐 `void swap(int &x,int &y){int c=y;y=x;x=c;}`
by Kniqht @ 2020-07-07 13:41:51