摘要：
位操作应用——异或http://acm.zju.edu.cn/onlinejudge/showContestProblem.do?problemId=4095Sample Input2aabcdefbzyxwvubzyxwvu4aqwertyeas fghaqwertyeasdfgheasdfghaqwertyaqwerty20x0abcd0ABCDEF0x0abcdSample Outputaabcdefeas fgh0ABCDEF题意：购买了n对袜子，每对袜子都有自己的名字（即7个字符）。丢失了一只，找出丢失的袜子的名字。首先想到的是对二维字符数组排序，这样很费空间。还有一种做法就是用异或 阅读全文
摘要：
拿这题来说事：http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=3421ZOJ Problem Set - 3421Error Curves Time Limit: 2 Seconds Memory Limit: 65536 KB Josephina is a clever girl and addicted to Machine Learning recently. She pays much attention to a method called Linear Discriminant Analysis, which 阅读全文