regex样例

Posted 2023-03-07 ~千里之行，始于足下~

#include <iostream>
#include <regex>
#include <string>

int main() 
  std::string input;
  std::getline(std::cin, input);

  std::regex pattern("\\\\d+");
  std::smatch match;

  std::string output = input;
  while (std::regex_search(output, match, pattern)) 
    //只会处理第一个匹配的字符串
    std::string number_str = match.str();
    int number = std::stoi(number_str);
    int square = number * number;

    // 自定义处理
    square = square + 1;

    output.replace(match.position(), match.length(), std::to_string(square));
  

  std::cout << output << std::endl;
  return 0;

//hyperscan的测试样例
#include <hs/hs.h>
#include <iostream>

int main() 
    hs_database_t* db;
    hs_compile_error_t* compile_err;
    hs_error_t err;

    // 定义正则表达式模式
    const char* regex = "hello|world";

    // 编译正则表达式为Hyperscan数据库
    err = hs_compile(regex, HS_FLAG_CASELESS, HS_MODE_BLOCK, NULL, &db, &compile_err);
    if (err != HS_SUCCESS) 
        std::cerr << "ERROR: Unable to compile regex: " << compile_err->message << std::endl;
        hs_free_compile_error(compile_err);
        return 1;
    

    // 定义要匹配的输入
    const char* input = "Hello, world!";

    // 定义回调函数，当匹配到正则表达式时调用
    auto onMatch = [](unsigned int id, unsigned long long from, unsigned long long to, unsigned int flags, void* ctx) -> int 
        std::cout << "Match found at position " << from << " to " << to << std::endl;
        return 0;
    ;

    // 使用Hyperscan执行正则表达式匹配
    hs_scratch_t* scratch = nullptr;
    err = hs_alloc_scratch(db, &scratch);
    if (err != HS_SUCCESS) 
        std::cerr << "ERROR: Unable to allocate scratch space: " << err << std::endl;
        hs_free_database(db);
        return 1;
    

    err = hs_scan(db, input, strlen(input), 0, scratch, onMatch, nullptr);
    if (err != HS_SUCCESS) 
        std::cerr << "ERROR: Unable to scan input: " << err << std::endl;
        hs_free_scratch(scratch);
        hs_free_database(db);
        return 1;
    

    // 释放Hyperscan资源
    hs_free_scratch(scratch);
    hs_free_database(db);

    return 0;

    //Match found at position 0 to 5
    //Match found at position 7 to 11

vector<string> findallstr()

    vector<string> vstrs;
    string str = "Hello999 obc888kadkfj777dkfja666";
    std::regex re("\\\\d+");
    std::cregex_iterator it(str.c_str(), str.c_str()+str.size(), re);
    std::cregex_iterator end;

    for (; it != end; ++it)
    
        cout << it->str() << endl;
        vstrs.push_back(it->str());
    
    return vstrs;