set vs unordered_set vs sorted vector

时间：2014-10-23 06:07:03

标签： c++ performance-testing

我开始想知道set / unordered_set / sorted vector之间的确切性能差异是什么。

因此，编写测试代码是为了比较它们的处理时间，以便我可以证明以下陈述：   - 矢量是线性搜索中最好的   - 由于散列

，Unordered_set最适合搜索 
#include <string>
#include <set>
#include <unordered_set>
#include <vector>
#include <iostream>
#include <iomanip>
#include <algorithm>
#define WIN32_LEAN_AND_MEAN
#include <Windows.h>


void PrintSep(const std::string& title = "")
{
    unsigned half = (78 - title.size()) / 2;
    std::cout << std::string(half, '-') << ' ' << title << ' ' << std::string(half, '-') << std::endl;
} // PrintSep

void PrintTable( const char** names, double* times, unsigned count, unsigned colspan = 20)
{
    std::cout << std::setw(colspan) << "type" << std::setw(colspan) << "time" << std::endl;
    for( unsigned i = 0; i < count; ++i )
        std::cout << std::setw(colspan) << names[i] << std::setw(colspan) << times[i] << std::endl;
}

class PerformanceClock
{
private:
    LARGE_INTEGER m_begin;
public:
    void Begin()
    {
        QueryPerformanceCounter(&m_begin);
    }
    double Done()
    {
        LARGE_INTEGER freq;
        QueryPerformanceFrequency(&freq);
        LARGE_INTEGER now;
        QueryPerformanceCounter(&now);
        return static_cast<double>(now.QuadPart - m_begin.QuadPart) / freq.QuadPart;
    }
}; // class PerformanceClock

int main()
{

    // -------------------- Preparation -------------------- //

    // Out inputs
    const char*  inputs[] = { "yxu45JRZV4tNdd1QCyna", "cnpcDiZMt7meuWlChRLz", "0A5tfP2dLXIz8koq64tL", "5P9bD9NNRtNfTujr5fio", "UZSnYM58N1meWIhY8rM0", "YQijNudHgBQwn6snPRH4", "xYI8H0Do6pi5RLZRECNY", "JRfGxQ2lDAD8gZwd6tQc", "NcCp2rwV4sP9PbiIuSEg", "i2cpej69faREswPiK7nE", "YdJAbj8E6VNQzAy9oeHo", "VNo3YDlyOeUeFA9BGiXm", "tB3D0j26nx610JPOOAIi", "pscv9tApKaxw14NSVlDv", "bFTCBs5o9mg14F6F4Plo", "f7TTZiWC2mMsvEAUGalq", "gxWkNu86l886MfPHdLzq", "tqRcYTo12xwwXVuEi2d9", "3Uz1t6tOQ7NYShZpUNuV", "aD34baQ18TMod6dfJwZA", "U1fSxmx9YuY1bsllgYar", "fhyEset0jR56qor5zjr5", "VEeQNIHipq2vy141rco7", "4LDjHmvLUe13NOr4SANN", "PoOthnu2Ke27bKEyWTDv", "NPWn9J52xHOOd4G5lrXo", "1xjnMU97qRYAxSmqi8TR", "2pj4vj4kVhwX2nkEKdK7", "Q0XJrYvEB0nzzkkFYlp9", "Uzr64OADHWHVHYWJfc77", "m0SKmbXZNiezdO77O8tZ", "kjPuw6dn4J8xwpRiSKuH", "KBaziJyAIyDlmz1Vzbas", "9qk3ZAK8VvKklXETictj", "1AYnAz8yr03j8ZAZ5iei", "SbhYkDkM63FmK3j3qsCz", "OMuqIu1ZOhBqBL6N1ytH", "2vxtMD2p8FcUVGIT0DnR", "AkrdF0Iy59gE7Dp9JNfM", "stH1IAQ0sXnSDaq1HMoW", "DcMMazqQQpbMzLyELrsU", "lJSdcCnUPhRhfzfSAXQF", "0UVIPfSSXA49eUsxe08K", "wnnfBEKK3Qp473xCFrVY", "wIX3U63r6tkWkIED9Rx5", "XLQF7G8scQrtPXPlIxfC", "FAX2XBVwqKzW8JrgJv48", "deaGGIl8KtPg16C8W3MJ", "AerQR94BvVuf5Zh09L6l", "MA4xrjmVJrDGwr8NJAjE", "liNhTpfwHCULOAGqiGGP", "bimfAY9eGu6fJBg6WV1T", "2B5m95znEnZluRif3cXk", "wGRrV7CiyVC8ibUPJpGU", "TTPxXJzvwCHYDnuTS4ze", "PSgfebaPu9X6ELwQFuhD", "6BNO39hyTDCkuVEhotFe", "HUTInCGeZzaw8os8Lj59", "5BulRf0hkaMVD70EWtW0", "Udge2C4oYujCZtJsPxYf", "4zOYA7utkNX4HAiYWJw5", "vGfHy2MLBYkvzodgN5NN", "QoEGnSP3NJEFwg90XsvP", "Z9MLyLnGBYRzoqeFfGnl", "sCKTWuio4aQAYehB6HCg", "rxzz7ct5IUDy52z0Ybid", "JzaimU3EAYScyPzLxnxO", "4EupGy8hKzovI04s9k3r", "9IyD9IyOTgHGs04AphgW", "wIPaqb92cpn3rA9G3xCJ", "NZezYsWHaSRKtZmlqKss", "K9wbueWp8R88e5imzrHt", "IltUiLOPFRNgQ0jOSt6i", "mrMxaogf1on4sfRx2wvv", "RoLK6lfBBvlE0sUT7hmc", "nJuFEfmfapBMtfxhrLLc", "8oltcyHy1WrVmLNlwhXe", "Q2wniXYZEE32fF0VO9KH", "ithGCjUE8j298nVEQ9za", "oJpwIUdXj39iZ5LEI5xP", "w9gXZxxqgEYXyHkv0E1y", "dP8vwnG0EaetT76YEoKG", "9JjVSweM2bhPQ5wfXZCl", "sCGWtGhdGpEpbC3bv35E", "wf33sMLLuWFEr9mQ6chF", "4lp8prBsejxikiyzdXKA", "zTylzgjl0CT7nO8SkXkm", "Uz0mc5OjfeXS7HkvuqeT", "VIHlV5xgEkiEZhROZ6P9", "vOM2TmFVULfdUJOUg46i", "arZEAcfaQBjfrOffogxd", "w4uBjsZ3rtLFe4PccEey", "yNT0fvxWXVfoSlkVhJwS", "Je7rcoWyxdh82fJGFkNI", "XRlbaICPD9tgHS4QiCoK", "7Vtkdx5fhGM14xRj4rEU", "Q9izPLm7IdVDP64j2XQg", "vp0IJz5UlMunNPuKc1pN", "69zhS3u7fylfFivKagx0", "lr1PwSfqVqNSucWJlGfA", "3iC5lr4tMVviJ2c2kmau", "JJQdbqP2ZjsdMJCdBkFi", "SoSUhRDhOvhArYUtRhtX", "x4fL4SEmo0QiuwAjjj4k", "oI4mbLwhg1QSWVG66SGr", "U2CTAPb1OkknT9pWXBDh", "Pk6TEh0IQmjO8EQP1agb", "o7JwwAjC2LGztObMw7qD", "UcvXFYRVJGqR0lejzvX0", "UqN6wQVfkJnPHzL4WiX6", "nMVsuJNNxXDIYzxMEfvp", "MhYxQdpTV3Ohpr5RAMTx", "HJ8KmYdSqKRh9fz6zlby", "SfeDgzAUQaxiWFiuY08K", "tgJuCx1UaaHVcKo1IPlm", "X6VUsOeAsFTkco7imijI", "yVEOPiM6DOB1UYVhhdk8", "fZRbVxqQFkSr0FRifnCN", "7Izg2Uie5JJGHlG9n7AI", "K7KTsWgcrhSHTTiRSrxt", "Kw0lhrJyE2TzQ2MoqA36", "KTZKnzmPwOmpDm9RhPL0", "XddDsauu6KYBxgR7QgOh", "x577aT0lJuj0AYFAk0TW", "dGlFYstHsmmEsnyisYek", "LLc0mK0pc92AudxCDgO7", "UFCuUiloKuVDAGBdQDnY", "icuNcxGj1xNRkackFEUJ", "WmASq7nN85SlcydJYMDe", "FuCxoPVfxvp74qXVHtdE", "aMPEltF2gFFpwhllz3NS", "Fd1YBdagkYrgcVzZ993f", "P3vEWtm49IoexbAVfWjH", "dPcjFfijFPP5RBPNfAjw", "r1KxB5TgKxbZgIh7n8Kb", "gnEGgTPg0OOtIVsTjbGz", "CDzf6PXyrdXpcG9yOb9k", "nwep76VGfJVvzWrm2ci3", "lH17zVrR57AF4eM6OQQL", "rt0hvdhbYM4MZQ2MNQCA", "XjUwspBBhyXxJ3A4sZcW", "TO66uuWsDb18XJgpZxx9", "PqoTmpxTI526jV46CeD4", "wowLbTpF002PgJeV3NOA", "fVFaW9edrWmj9DagF9Zl", "2wKCKRmuUHXl25H1vzAM", "2iko2TR11skm4CjE2iuD", "hGSyJuZdvSD882TcCx7l", "0aSM7AgV5pvxYYS011Xm", "gIKHT5wi33d2dHglU3r4", "tPuRqjFsGCEQRjVsVt4n", "s1yuSwWO1sKvvD7ijGDv", "Xy2tVRxiRhLpRQ67cgBe", "dN0ZtJWX47Ry974J8grz", "4oALvEi4rsE8q4XV9ibo", "QA3fwYSPrxewIwhl5M33", "MKxUjD5VBqOCBcOSgskP", "i4SUZJ7XjJYHuT1Myd6S", "TAmdTTSwiCTyy33nNKug", "rcRjMeBQMssJZPLTX7Eo", "YWszqu7Jk5qGznZVyRkU", "zkSXYxFFX1u2TPzzekFr", "iwpWWlMTQiin1gP1B725", "dguvfNWyX1F9Kq8CUmio", "mmweJmmGCXfzkiWvrIAf", "0jqq0zp3nI2w3iIG01ev", "I4bVHz3KajVm6f6QPAXS", "QrQtMNo3pGGZjQtYJvQm", "IZyZbFhK1ou9Vs6hU5XT", "JKjlvweHcnxdFtUVsCNu", "lGMqzOFQrq4vvRDujiCW", "zjO04wpUHtUn67bETAdg", "n7ysAW4ml7S8BhwE9ubO", "IjRGqKzqLimHeaTyffcO", "QL25AdNDTwuze9JWNjkD", "q948zpLcMQX0ImQyVaiO", "dUgKdtOzKiiLqONbOkIp", "e4X4df2DzjFzv2Qk4OXw", "d2L8oJgGpIs0qkycSMxN", "kqIYJQDnrGo22j1jA7cF", "Y7gfGAsXWmRNLqSJr0gy", "tZdaBU23aVFajefzyLOF", "qZvD1NMV1uwUD0hgawmw", "sdPIN2HTZE6t2b9Djz7s", "upAwEn0o4KSNdahAC4DW", "Sahw60orUZ8jfNg3t5tC", "otAVTH99oIm0pmLjpxuq", "5s9zcaoMQPJaxYZIizLr", "0INz5juLXNS1qz0S5ZBD", "sdfeGOkVyogYIGlZuKQR", "mrDeLJd2vhobT5pkmHUg", "X4fz8JUHXym1ReuSIfl7", "qW60yaRPSvxnEe93hxsL", "exmEIAOI9PRZFX2Q2ahQ", "PKgWxvU1QFhyrnBkzoon", "OCZBJ6WSnfHz5JN8hrSg", "BPRi6d3TmbAdC2kASDGv", "jCwBs3QNbLLL1BS8ZsWY", "VHmUgSk71PzHpsaVEQaP", "SSqA6435huQqguErI5Om", "j8EWadtp9N09Kg3TionW", "paUS1pfKLqvvRdCatNEA", "U4m0QB6bhzLwcJw8PWUd", "FzMv6nkQOZZ08rbnZzfQ", "JDX4rjAgRIj9484NnN0B", "t33jIgbYP7uK7aU4uPqf", "Jim3d7AbanwSA4dsgYTf", "s79GzWjCnNzCqMP02uXR", "pwV3gzOWRPInyIRab3hl", "KSkC3a1NysnHXmg3hz00", "48RohG5tE4mD1FW6gDxO", "edySUYmPSAWb2SNABx3i", "ZewnjFRsNF2P7FsXFG1J", "P3MKpt0pjsWjCxmzFH1k", "OM9ZkaXWStkeD2D44DQr", "5uLXwJks9bhxGbkbx3PQ", "uwyllRDSx3Rdk4tkE2XK", "CebMT43q8FUOZwC9I3hD", "OP99Uiiau2L86Jb1HLDt", "mNStmnQK57wNhY1xgiWr", "bkqIbxcsGn7a3oUsDUz9", "8B6Nh2fr32FDxa5Zk8EO", "WmoIHtvZBVbJznqn6MDY", "WAWNAksIY9TloCHPMdDp", "h0X2FSzQBGfg858Zr5lI", "U4guPLRmEiWpmwkVfXsk", "07PY0E8w0ynsJJJG6dTT", "1EwuMIgLzZ4QOLSz9KKK", "ZbgGBA5PkbWOAgKa6U3U", "2YP3z0RaIinIJHndQvJ9", "VuTVO86yXm26C1ZC42cv", "czszyFqLJelsDtkB1wGm", "JBSSs9Gq2z1ho5vxKa7b", "WxzstpP8LNFek2sNVO7I", "SdR4zJAFYIUC6Ox7F5Ao", "bqeQdAHhSqq9CMH466EU", "3osfIgWhT0YYWHLuFp6m", "OsYQp5s01CyQsAxxyJ5z", "QmdGehSItOI9ytDJx2tn", "RS7NTVDlt0ae7mG2fNu2", "b70uAiLvD8lWmD4LFhoq", "qYA1LVo2Zk9Yka5qJ69M", "2QteJBZyvfLu4QnwuXZp", "spE7TmutGb9sF3l1WdzK", "wx7fwsIzuPHCPoJMm8Zi", "UTXxyVIFT1MP3piFOj9E", "Sv6X1tpRqaIFKVvOjpy0", "zkCCginO8RH1IQ5gxP9n", "lpzHz0JOAKDEbNzWOLHi", "ga9ThbxxkMjZBISnpM4Z", "XLj9Dc3gI3zspCQUqLAy", "I4B6seBrJYopMfIJPRg8", "y7oFbP2hnfLIx7Loufzb", "qwENxA8OA4xGHB2Y7T7z", "TCJca2HMVXLoBLLTQaMm", "Nm0YLJ6zdfj5EkdYReJR", "04rQlakEagJimcZi0xZF", "5AotlztHKO5FCed44T51", "IIhf1YB3yq0MfKBMDiNJ", "gI8dJJVL8oysEkUROyFF", "ls3nHBIMOdtdd68wSJ8B", "sXt2Pgcq5GLpPRXPDEfX", "RRGLCAXtrjBMtj1UoWWP", "N6GGDjSpvxPrtPFtiBuG", "KM7aQq96bzzokQSkXy2L", "THGWpDuXfiq7ydRtYzGN", "4EDerDQt1cKbzO16436h", "76rXLODN8Ik5KjPKipo2", "k3HKxP0Ek5jSviq8F0Z9", "Tt6ax6fUn2ifsfBoLuZJ", "vuChGzc9hlKnerW0FTS7", "osXjEnlYYN2uLShpDgPa", "kyRWc0KCtFBLtFXHTYbG", "ArJSG0mJY2gUHSJ8MkXs", "nQea6CLRuer8f6clqd3T", "7WIwE0fUplMqQ8HDJyl9", "JoHJzGl8hLk1b2yiea3b", "8AW3Ip8YLf1wdRZkFr0p", "EwyYE9FdzBppUhpmEQkY", "ULpmmACM04oxA89Of4vR", "1ETapZcpVUCMkKY0AAcx", "9u8SaUc6mUethl73dyEN", "SI2EJys3uWiAf93l6G3X", "dc5sWttEbc0ixIdw1YqV", "QV3FRwytDAA3TCsy4jiQ", "KO89nRNbn1sb9QqAnalZ", "fJtl4TSxF3nkStQSZjKV", "W3Zv9VIIfVVDfHYB1MZJ", "Sru5BIe1FBt55353fZBR", "8hbYFsKp0a69zFf8XfME", "SgAxktG5TWZgdT75qlnk", "IlB4M3cfYRsEacB5mxKQ", "v2eSPv7LNCZpJvaIxhNq", "qcfHQFRTaf8hFUC1uGeM", "m309qZaNJJdKVbkqIh0p", "LPRXLy1JxXAgjOpD4SOh", "V3JDPm9ZT7xEF5TGjmQ5", "pm8asJdQlQYP3GAQGg7B", "RNg45uLlAynFdQEiAd1z", "MsBlcLHaoRvarn2Hg9cv", "sptoqa8m9MQoo0Qdv6W5", "LQBNbdGTPe8wd1RnOWL3", "AzzwJ2xV8hy3CZQrwaDJ", "ZcIsPuJn76TKGmTW2uc5", "412GgdvECB1N7g2Q136N", "XLwiWSaE956lBioeusMg", "C8Ark7jlgdKLbw79v1Ga", "Rpgw0jCzvOZywBS1R2cX", "nhXbq1ZmUSnUbBOWmCss", "0EngfF85ZVCv42Gd8LiZ", "JmCOkPve5IWSe3AaN7HM", "iHMI9zUHEucjS64Zq65T", "iRZQmbtj7mIRxYoNXNCW", "87S4t3SekcuxRFLm4Vj8", "pq0iCznEdH2yqryur0ut", "MZ8JUEXA4NvSFJVvagSo", "wYh7K2VqClA0NT2YNz0x", "lEXFwt1QvyLorSrSDxtJ", "Jo8ZBFuR4AdGAlSPrEra", "5OFujFQGmkp7yFpuetg3", "AdBtAYEvesYLPEBQeYve", "yDh3QJ34463eemMIKuI6", "JpIOLAZKKVRw4W83z45f", "0pNXAVcaEnx1xR5MuCB5", "vCj8Lf24T7KfnqDPjLw3", "YOLVtf9CAGxusaJ41VNZ", "82Y5ryW3Li729CEchqti", "kuwMAYq5tFWiSNkSEUGj", "zPXdbe0Ce8iCnNymn6RS", "r6oIYnbLMUvgK5fAhUYX", "r7zlqTEbleJEIQlwTRvx", "P7qHubtylXZL806S2i7z", "FOwjwJ6XHA4YPmeosKCh", "3XNFLqoIJCNXeLT1zcYf", "LimUsGLXzPVwX9wWXMmG", "GPVnnjTikZepjomFMM3G", "ppXlJWH4qbARPsCzrVfP", "bgaHljMhHsBfCN233pGy", "71O4ZgWSIF6pJTHqQCAv", "hgfbHneNpEkaoTjEGi35", "BP29PdJMnGOP8OW8gLyB", "VfrsHKOpMT2cylXUZyNZ", "WZDrZ9SFsEnAWi9EDv2c", "VpeRIGudekAM39Q8JoVy", "oGr06UoFSyt7B7fdmDxE", "rZ21EQAMR2TO726ORH4X", "7GSsIES5eHzhQMfCFVlU", "Ne5DGZdduwtJjeWxoF9r", "SZJ3eKgHGQgXz6mwWQJa", "5tc8iVyeUu83ZX8VGPGa", "1we37HKSas1jzOK3oJ5a", "bAzWv0LXBBFtlQazyXfE", "dKpMfN8bsa2U45RYkSIW", "kyRvCRKKLeB8tO20rB9I", "NV8MBc1pcI71FQYHlWnq", "q2hk3QhTC9lXU85ozlYd", "AhKuywGqS75a3U9PnBaQ", "pfaqxamqrbQFEKyW57fY", "99wBwml3fglePRgmu7ra", "AQAQDqi6L3coCDdDZns1", "pzz5npWyJ6VQPxo74Cke", "GWciE16vRqm8zrHA2NH5", "0kLpyuzVksayvw1fIbgl", "jJb7R3CvU9qHSHEkZhBA", "0I1I7DTYHtzFkiK2vj7B", "4OPP86obIIhBtpdkZRjV", "53D7grILbzHEYjH70Z7g", "n8jUOaamiQksK1Ol5ugK", "XvTe9iN83a8AF7DqFuxM", "yTnjXNaRWHYTQLuomwY3", "6BnEAXXeLFHCc9V33wXx", "E8Ii1r0t9KmUpSO66TKp", "Xk8jCTYopGN3UQX3fQFL", "4dlTkv8BD6tJG98eewke", "aigrOBHoaY0PFEiUm1N5", "osSxqwTcADgvxdMpaKun", "gYHjw5dKudsqKpNROs5U", "ZEObDNpngRApsxWQUqYd", "DC2OG9A2gorJvMAhMqDd", "qYS7T9XKxGmCrLeWndMy", "k9zdcJpkeV7lNpDqu0IC", "LNbnfk5MwyYqHYKdzJG4", "rlZCUvoY0tX7G6XNpKJx", "ZijRJkRmIpni8KDi8bfH", "2CEw7UMYw4IxKsJec6ob", "P3wa9NXkNceWuR1QvFik", "TbK8qSIydMH2ZjN6H2ix", "N5xXx7t9R5aTG0rHqCoA", "IFAjLEo7FuvDCZ3Gz0WR", "f8VWdjXfCXrb9NNkZfX4", "ODNmQDPJ8YbpHrqATVpy", "MIeomMUJskj6pm1hWII9", "vd7FVv3Yq0eaanek6OqM", "gXAFmO9JU3I0kTmRg0RD", "lpYJpvX51YNCYwn9Smgm", "ZIZQtPl8b7pl9cRQDpLg", "6hRbFMiQILcHwfaIWKVH", "xRMJ6qyR7vTCZac8HA7x", "gVc8ZOawXNXBrzUfFuNx", "AHYMYtupBun7guGcGejk", "qB7nzqIm8bSIZzrK2DQc", "rMdCVKrMqLOhInvlQ3eb", "jceVpW9Yv40Mxhue4KiT", "EF35hrtvfaRoEto0SMXT", "Fr9U1rpOOpekZw8GYUbX", "cPiHqe3n1hzGImsptJxB", "cQs2Iit2w5SBlZFd489V", "1Xtoozu8YUB5SAWux8gN", "LTByKhkhNsoxjI5Xc9Ar", "L0dtCYu4IxH5Tx9yp300", "U7Plnx2BfU0ZLT06DVjc", "XL3cL6ycniVo9FVGGmOC", "oldWUOfn24r7wmzlOamz", "2bAxMYiU0DifA8vOp6zm", "ldYJxVP1liqZaBtGr7pv", "khkPHtoOrhqbJim6P7hf", "QAtcZY93vIUr6G7DQ79D", "CtIXVqE81TLHsLajFuKZ", "MtI3raq6Idwwf3O2Bez2", "8VyANkZDN3CUXSib22fB", "iveiownGGZArYd6OMA68", "NbJROsiZikke3jnsiG50", "0tsaeEt6TsMTBhyD0vHk", "XYpNa6xNi3knrKIGoIJ7", "L9Uqgmerw6sAlCmT7TY9", "nzJhgYAEcHqFSzaIy9ZN", "bohzQ8Xz7tCl4uujGj4e", "zl79sgjTnmFxtrgMOrTp", "Mbor4W3HaMgJTRbyqg3l", "GJJswSQacWn0XoD8qFBK", "1J1Hi6SzromDpPpNuFko", "FyyvJWEk9H7nnUGw41zL", "bYuEX8u223s9HVFa8DoQ", "CN0grWgSZH8QK1IEfPwz", "2dcfAvjZS74upCBEs0pJ", "9SOyYA1qf71DQBbbF44R", "DSZPICvixvRbFcE3GZ71", "5ePbE2qCMg3PlhFjvdcg", "Ee1Cmlh7Nw5lQe5ph44T", "x6HrkJBvkPzOxGLfzudt", "HQhBRPa7A0qIoGAB6HHp", "y2EV7W4n6uUwTCr644OB", "iuoLYFYMxl0jumIm7nlD", "pPnvUEdVnwPM5FnMQWIX", "y54cO4vkHpNMqsNRPq44", "eSOP9svhDeKvwlo7zZr0", "cvxRkDvD86cARbS5C9QD", "bHQ0jzP8yYsHqa6cePm9", "qQ3ExNc4Zg5MlWRrWHwI", "5tv0MCv0y6GU2DczrfrP", "l18w5yXH92Tuo4PjpcA5", "CjmsIFwzyJbYzk4Z3cRC", "bA6rZYeQDeC96Dw0snMD", "B1NKqfzOtCovciSQTs2D", "eCzLXBLTvv08ubXDjauH", "m5tx9YJ3CCvgGGpd2F3d", "IZ1Tq2gYgRjYIX3rkGgU", "XgUNhykvIJPFTh07W4xV", "gRkMoVoJbwrBAbCCYtFu", "MEY1mjGeGLFKrimnnIhi", "qlhv8fh4zp0neZIMz5TN", "f1o74eIyWp4j2M49PMdY", "Zy6V98O9sZ10TPuAL1BN", "q6hVlJcPyw7jcqTkwIjB", "X58lDP8cc0AaNtOTPdWG", "EsaklDto1n9KW23y5Rlo", "owi5TngTQK1Yx4SDX6cU", "8q4aatZrm3DxaF8MZqaH", "qHvQxvr52bxbn2Lsz894", "5t7ZhLjwyD4aEbmnbZ8U", "Q4IXLuJ0m6R2LyDIEN1M", "3qlSpGC75FJf35tsESjs", "wj0TVvNPNCFIqdSPzAPW", "fknkisTHnOkouphJ34wi", "aDLCLpGsidQpQMe2buHd", "9bF9XvgkmSk2QaH6b95M", "VO4EuELUxseX8Hjsxe2k", "U22yTKWTUN0pNiQxVSgM", "2hKQqNzCC9qeBWpdFJ4p", "UzCHLW5Uif2ESwvWtMTd", "aeiKCJHqoy5B9UmTSjRo", "VPIaKy589JQSJMOeoLiP", "amFmEUARPm1DjQwXefEg", "M1MTKIsulq4oeDGBkFYy", "hbjLnR2Qx8ZSTjnrsFci", "QEDiz38W4pIBXVRab21U", "lNYCJVRcnBtrxJTsSW8z", "lZKlnovVYV8Rdg9iSpzp", "ZmpuelXNs3MlZU6GcqxX", "uWcwVLBXWWqrkSyAGexd", "H91lUOJFN1AJtyQJ2yrY", "qUOpBXvkdKZe8OsRovc8", "VreNCHBV3pp12fk8Ax6I", "tlgHjVlArf2RagO3jBPZ", "kUjymJiFXv52PgpDcY9z", "5EcD56ZTtObcOq5BxZJt", "wpuNhRrKaUj5yd0QbnHZ", "AIYwGTo9Yt19mLaTkzNI", "zpaJZRLZiMHmhOQ6Jy0j", "6On0n4mUeK4Ics8Q725j", "X560iPqFqijgxv7FXiUn", "HyljDZCwDOKb71iHV2Tm", "kEzYhJ0k8KASaMamU3I4", "hfIuWLaeZtD6hUy8umMw", "87wS1xCo3wZlxPyCO1fj", "5Q6jJZvKQgaI5JgEZLjX", "vmGReyRElWHslAjFGPsp", "kSn4oUIWAfSev6MeaNym", "5ltdUwNsFaV6gHoxgCMI", "zFzljs3uCXXIOBlXTFjm", "r0cGBofX7AWMyQ80ciyC", "J0xgBJOhM1ApHj9ccP8w" };

    // Our candidates
    std::set<std::string> my_set(inputs, inputs + _countof(inputs));
    std::unordered_set<std::string> my_unordered_set(inputs, inputs + _countof(inputs));
    std::vector<std::string> my_sorted_vector(inputs, inputs + _countof(inputs));
    std::sort(my_sorted_vector.begin(),my_sorted_vector.end());

    // Time Utility
    PerformanceClock clock;

    // Output Formatting
    std::cout.precision(std::numeric_limits<double>::max_digits10);
    std::cout.setf(std::ios::fixed);
    const char* names[] = { "set", "unordered_set", "sorted vector" };
    double times[] = {0,0,0};


    // -------------------- Binary/Hash Search -------------------- //
    PrintSep("Binary/Hash Search");
    // Find all from set
    clock.Begin();
    for( const char* s : inputs )
        my_set.find(s);
    times[0] = clock.Done();

    // Find all from unordered_set
    clock.Begin();
    for( const char* s : inputs )
        my_unordered_set.find(s);
    times[1] = clock.Done();

    // Find all from sorted vector
    clock.Begin();
    for( const char* s : inputs )
        std::lower_bound(my_sorted_vector.begin(),my_sorted_vector.end(), s);
    times[2] = clock.Done();

    PrintTable(names,times,3);

    // -------------------- Linear Search -------------------- //
    PrintSep("Linear Search");
    // Find all from set
    clock.Begin();
    for( const char* s : inputs )
        std::find(my_set.begin(),my_set.end(),s);
    times[0] = clock.Done();

    // Find all from unordered_set
    clock.Begin();
    for( const char* s : inputs )
        std::find(my_unordered_set.begin(), my_unordered_set.end(), s);
    times[1] = clock.Done();

    // Find all from sorted vector
    clock.Begin();
    for( const char* s : inputs )
        std::find(my_sorted_vector.begin(),my_sorted_vector.end(), s);
    times[2] = clock.Done();

    PrintTable(names,times,3);

    return 0;
} // int main()

问题：

  • 声明听起来是对的吗？

  • 此测试有效吗？测试会受到编译器设置的影响吗？（在visual studio下）测试是否会受到编译器重新排序，优化指令的影响？

  • 除二进制搜索和线性搜索外还需要考虑哪些其他测试用例？

2 个答案:

答案 0 :(得分：6)

  

声明听起来是对的吗？

     
      
  • Vector是线性搜索中最好的
    •   
  • 由于散列
    • ，Unordered_set最适合搜索   

是的，由于连续的内存使用/更好的缓存利用率，更少的指针追逐，矢量在线性搜索方面表现最佳。它最擅长二进制和插值（也称为外推）搜索这些原因以及支持尽可能快的随机访问（即[n]），但获取/保持预先排序的元素可能更昂贵而不是许多其他容器。

unordered_set需要哈希键，键值相等检查，并且对于糟糕的哈希函数或恶意设计的数据集可能有令人讨厌的最坏情况行为，但总的来说 - 随着元素数量的增长而越来越多 - 它 更好地搜索特定值而不是vector。

  

此测试有效吗？

没有。它有很多问题...例如，QueryPerformanceCounter在大多数Windows PC上都不可靠，除非您将流程绑定到特定核心，它不会折扣您的流程暂停的时间而其他代码运行（如果您选择了错误的核心来固定自己 - 系统管理，驱动程序，中断处理程序以及其他进程）。此外，可能存在缓存加温效应，因此在信任结果之前以不同顺序重复基准测试是个好主意。结果还可以反映特定键类型，容器大小等的结果，使结果不适用于其他数据类型/集。

  

测试会受到编译器设置的影响吗？（在visual studio下）测试是否会受到编译器重新排序，优化指令的影响？

当然。

  

除二进制搜索和线性搜索之外还需要考虑哪些其他测试用例？

排序向量允许插值搜索，有时可以更快地有效（例如2-3x）。根据您的需要，插入时间，擦除时间等可能相关，也可能不相关。线程安全。数据类型和哈希函数（包括您是否需要抵制恶意易受攻击的密钥）。所有这些都取决于您的计划对数据的整体性。

答案 1 :(得分：4)

首先，代码中的循环没有副作用，因此允许编译器完全优化它们，尽管在VS2013U3上我没有发生这种情况。你应该添加一些不会影响性能的副作用，例如：

size_t len = 0;
clock.Begin();
for (const char* s : inputs)
    len += my_set.find(s)->length();
times[0] = clock.Done();
std::cout << len << std::endl;

其次，使用的数据集太少，因此测量结果可能不准确。您应该使数据集更大或重复搜索更多次（并且您可能想要同时执行这两种操作，因为这些操作的效果不同）。

相关问题
最新问题