string search.

本文介绍了几种高效的字符串搜索算法,包括蛮力搜索、Rabin-Karp指纹算法、Knuth-Morris-Pratt算法、改进版KMP算法以及Boyer-Moore算法。这些算法广泛应用于高性能模式匹配场景,如入侵检测系统。

This website is a great resource for exact string searching algorithms.

High-performance pattern matching in Java for general string searching, searching with wildcards, and searching with character classes.


Program Brute.java is brute force string search. Essentially equivalent to SystemSearch.java.

 

Rabin-Karp.

 Program RabinKarp.java implements the Rabin-Karp randomized fingerprint algorithm.

 

Knuth-Morris-Pratt.

 Program KMP.java is Knuth-Morris-Pratt algorithm. KMPplus.java is an improved version that takes time and space proportional to M + N (independent of the alphabet size R).

 

Boyer-Moore.

 Program BoyerMoore.java implements the bad-character rule part of the Boyer-Moore algorithm. It does not implement the strong good suffix rule.

 

Intrusion detection systems.

 Need very fast string searching since these are deployed at choke points of networks. Application

 

 

http://algs4.cs.princeton.edu/53substring/

 

 

### Differences Between `string.h` and `std::string` In C programming, handling strings can be done using two primary methods: through functions provided by the standard library header `<string.h>` or via the C++ Standard Library class `std::string`. #### Functions Provided by `<string.h>` The `<string.h>` header offers a set of low-level operations for manipulating arrays of characters (null-terminated byte strings). These include: - **Copying Strings**: The function `strcpy(dest, src)` copies the string pointed to by `src`, including the terminating null character, into the array pointed to by `dest`. - **Concatenating Strings**: Using `strcat(s1, s2)`, appends a copy of the suffix of `s2` to the end of the string `s1`. Both must be properly null terminated. - **Comparing Strings**: With `strcmp(s1, s2)`, compares lexicographically the null-terminated string `s1` with the string `s2`. These functions operate directly on raw pointers representing character sequences. They require manual management of memory allocation and deallocation when dynamically allocating space for strings[^1]. ```c #include <stdio.h> #include <string.h> int main() { char dest[50]; strcpy(dest, "Hello"); strcat(dest, " World!"); printf("%s\n", dest); } ``` #### Class `std::string` Introduced in C++, `std::string` provides higher level abstractions over traditional C-style strings. This container manages its own storage automatically, allowing more intuitive manipulation without worrying about buffer sizes or overflow issues. Key features include: - **Automatic Memory Management**: Automatically resizes internal buffers as needed. - **Operator Overloading Support**: Enables natural syntax like concatenation (`+`) between objects. - **Rich Set of Member Functions**: Includes search capabilities, insertion/deletion at arbitrary positions within the sequence among others. Using `std::string` leads generally safer code since many common errors associated with pointer arithmetic are avoided[^3]. ```cpp #include <iostream> #include <string> using namespace std; int main(){ string greeting = "Hello"; greeting += " world!"; cout << greeting; } ```
评论
成就一亿技术人!
拼手气红包6.0元
还能输入1000个字符
 
红包 添加红包
表情包 插入表情
 条评论被折叠 查看
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值