ch8_2.cc

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#include <algorithm>
#include <cstdlib> /* srand, rand */
#include <ctime>
#include <fstream>
#include <iostream>
#include <list>
 
namespace Find
{
    template <class InputIterator, class T>
    InputIterator find(InputIterator first, InputIterator last, const T &val)
    {
        while (first != last)
        {
            if (*first == val)
                return first;
            ++first;
        }
        return last;
    }
} // namespace Find
 
int main(int argc, char const *argv[])
{
    // time
    clock_t t = clock();
    time_t rawtime;
    struct tm *timeinfo;
 
    // 获取文件路径，参考：http://www.cplusplus.com/reference/string/string/find_last_of/
    const std::string full_path_exec{argv[0]};
    std::string::size_type found = full_path_exec.find_last_of("/\\", std::string::npos);
    const std::string exec_path = full_path_exec.substr(0, found);
    const std::string exec_filename = full_path_exec.substr(found + 1, std::string::npos);
    const std::string data_file_name("\\ch8_2.result");
 
    // 打开测试数据文件
    std::string data_file_full_path{exec_path + data_file_name}; // 数据文件的绝对地址
    std::ofstream fout(data_file_full_path.c_str(), std::ios_base::app);
    if (fout.fail())
    {
        std::cerr << "无写权限，测试数据文件生成失败！\n";
        system("pause");
        return false;
    }
 
    // output time information
    time(&rawtime);                 // Get the current calendar time
    timeinfo = localtime(&rawtime); // Convert time_t to tm as local time
    // printf("Current local time and date: %s\n", asctime(timeinfo)); // Convert tm structure to string
    std::cout << "\nCurrent local time and date: " << asctime(timeinfo) << '\n';
    fout << "\nCurrent local time and date: " << asctime(timeinfo) << '\n';
 
    // 开始测试
    try
    {
        std::list<size_t> ls;
 
        /* initialize random seed: */
        srand(time(NULL));
 
        /* generate secret number between low and high: */
        size_t low{10}, high{99}, num_of_points{18};
        size_t iSecret;
        for (size_t i = 0; i < num_of_points; ++i)
        {
            iSecret = low + (high - low + 1) * rand() / (RAND_MAX + 1);
            ls.push_back(iSecret);
        }
 
        // 先排序
        ls.sort(std::less<size_t>{});
 
        // 开始顺序查找
        for (auto itr = ls.begin(); itr != ls.end(); ++itr)
        {
            std::cout << "*find(" << *itr << ") = " << *Find::find(ls.begin(), ls.end(), *itr) << '\n';
            fout << "*find(" << *itr << ") = " << *Find::find(ls.begin(), ls.end(), *itr) << '\n';
        }
    }
    catch (const std::string &e)
    {
        std::cerr << e << '\n';
        fout << e << '\n';
    }
 
    // output time information
    t = clock() - t;
    // printf("\nIt took me %ld clicks (%f seconds).\n", t, ((float)t) / CLOCKS_PER_SEC);
    std::cout << "\nIt took me " << t << " clicks (" << ((float)t) / CLOCKS_PER_SEC << " seconds).\n";
    fout << "\nIt took me " << t << " clicks (" << ((float)t) / CLOCKS_PER_SEC << " seconds).\n";
 
    // 测试结束
    fout.close();
    system("pause");
    return 0;
} // main