study
POJ1006
POJ1006 Biorhythms Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 124772 Accepted: 39392 Description Some people believe that there are three cycles in a person’s life that start the day he or she is born. These three cycles are the physical, emotional, and intellectual cycles, and they have periods of lengths 23, 28, and 33 days, respectively. There is one peak in each period of a cycle. At the peak of a cycle, a person performs at his or her best in the corresponding field (physical, emotional or mental). For example, if it is the mental curve, thought processes will be sharper and concentration will be easier.
POJ1458
POJ1458 Common Subsequence Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 44778 Accepted: 18346 Description A subsequence of a given sequence is the given sequence with some elements (possible none) left out. Given a sequence X = < x1, x2, …, xm > another sequence Z = < z1, z2, …, zk > is a subsequence of X if there exists a strictly increasing sequence < i1, i2, …, ik > of indices of X such that for all j = 1,2,…,k, xij = zj. For example, Z = < a, b, f, c > is a subsequence of X = < a, b, c, f, b, c > with index sequence < 1, 2, 4, 6 >. Given two sequences X and Y the problem is to find the length of the maximum-length common subsequence of X and Y.
Linux下获取一个程序运行时间和内存用量
思路 运行一个程序，然后fork出一个子进程来使用execl运行目标程序，然后使用wait4获取子进程所消耗的资源。 目标程序
POJ1961
POJ1961 Period Time Limit: 3000MS Memory Limit: 30000K Total Submissions: 15006 Accepted: 7158 Description For each prefix of a given string S with N characters (each character has an ASCII code between 97 and 126, inclusive), we want to know whether the prefix is a periodic string. That is, for each i (2 <= i <= N) we want to know the largest K > 1 (if there is one) such that the prefix of S with length i can be written as AK ,that is A concatenated K times, for some string A. Of course, we also want to know the period K.
POJ1686
POJ1686 Lazy Math Instructor Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 3766 Accepted: 1307 Description A math instructor is too lazy to grade a question in the exam papers in which students are supposed to produce a complicated formula for the question asked. Students may write correct answers in different forms which makes grading very hard. So, the instructor needs help from computer programmers and you can help.
Simple implementation of ls command
Just an assignment from my Linux programming course. I have only done a small part of work of the ls command, after all, it’s a program with 400+ lines, if you want to study full source codes of ls command(in which there are 4000+ lines codes), you can get it from here.