如何以最快的方式在C++中创建/初始化自定义对象？

huangapple
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英文:

How to create/initialize custom objects in C++ the fastest way possible?

问题

I have a function that creates a vector of Nodes and Edges from a vector of Profiles. Its working as intended, but this function is by far the slowest part of my full script. It takes around 150 milliseconds to run.

Machine(s):
Linux PC:

  1. intel i7-12700k, 128 GB DDR4 3200 MHz RAM, Ubuntu LTS 20.04

Windows (WSL2) Laptop:

  1. Ryzen 9 6900HX, 16 DB DDR5 RAM, Ubuntu 22.04 LTS (8 GB DDR5 RAM)

Both using gcc compiler and CMake and std=C++17

My source file that is the base of my entire program:

  1. #ifndef DEFINITIONS_H
  2. #define DEFINITIONS_H
  4. #include <string>
  5. #include <vector>
  6. #include <string_view>
  8. // ... (code omitted for brevity)
  10. typedef std::vector<Company> Companies;
  12. #endif // DEFINITIONS_H

The profiles.h source file (have not included irrelevant code):

  1. #ifndef PROFILES_H
  2. #define PROFILES_H
  4. #include "definitions.h"
  6. std::pair<Nodes, Edges> create_edges_and_nodes_from_profiles(Profiles & profiles, Companies & companies );
  8. #endif // PROFILES_H

The profiles.cpp file:

  1. // ... (code omitted for brevity)

Now in my main driver:

  1. #include "definitions.h"
  2. #include "profiles.h"
  4. int main()
  5. {
  6.     // ... (code omitted for brevity)
  8.     #ifdef MONITOR
  10.     auto before_creating_edges_and_nodes = std::chrono::high_resolution_clock::now();
  12.     #endif
  14.     // Create nodes and edges from profiles and companies
  15.     auto[nodes, edges] = create_edges_and_nodes_from_profiles(profiles,companies);
  17.     #ifdef MONITOR
  18.     auto after_creating_edges_and_nodes = std::chrono::high_resolution_clock::now();
  19.     auto time_creating_edges_and_nodes = std::chrono::duration_cast<std::chrono::milliseconds>(after_creating_edges_and_nodes - before_creating_edges_and_nodes).count();
  21.     #endif
  23.     // lots of functions using Nodes and Edges 
  24.     //...
  25.     //...
  27.     return 0;
  28. }

Note that I am not an expert in C++. The code shown above works but it takes a significant amount of time (~150 milliseconds). The rest of the script combined (around 15 functions) takes less than 100 milliseconds.

My question is basically, how do I restructure the data and/or the initialization of the objects so that it is as fast as possible.

The reason I am asking is because, I found it impossible to find how to do this on Google. It could be because I don't know the right terminology.

英文:

I have a function that creates a vector of Nodes and Edges from a vector of Profiles. Its working as intended, but this function is by far the slowest part of my full script. It takes around 150 milliseconds to run.

Machine(s):
Linux PC:

  1. intel i7-12700k, 128 GB DDR4 3200 MHz RAM, Ubuntu LTS 20.04

Windows (WSL2) Laptop:

  1. Ryzen 9 6900HX, 16 DB DDR5 RAM, Ubuntu 22.04 LTS (8 GB DDR5 RAM)

Both using gcc compiler and CMake and std=C++17

My source file that is the base of my entire program:

  1. #ifndef DEFINITIONS_H
  2. #define DEFINITIONS_H
  4. #include &lt;string&gt;
  5. #include &lt;vector&gt;
  6. #include &lt;string_view&gt;
  8. #include &lt;string&gt;
  9. #include &lt;iostream&gt;
  10. #include &lt;unordered_map&gt;
  11. #include &lt;algorithm&gt;
  12. #include &lt;utility&gt;
  13. #include &lt;immintrin.h&gt;
  14. #include &lt;chrono&gt;
  16. typedef std::string s;
  17. typedef std::string_view stv;
  20. struct Experience 
  21.     {
  22.         s from_date;
  23.         s to_date;
  24.         s position_title;
  25.         float duration;
  26.         s location;
  27.         s institution_name;
  28.         float salary;
  30.         Experience(s from_date, s to_date, s position_title, float duration, s location, s institution_name, float salary)
  31.             {
  32.                 this-&gt;from_date = from_date;
  33.                 this-&gt;to_date = to_date;
  34.                 this-&gt;position_title = position_title;
  35.                 this-&gt;duration = duration;
  36.                 this-&gt;location = location;
  37.                 this-&gt;institution_name = institution_name;
  38.                 this-&gt;salary = salary;
  39.             }
  40.         
  41.         Experience()
  42.             {
  43.                 this-&gt;from_date = &quot;&quot;;
  44.                 this-&gt;to_date = &quot;&quot;;
  45.                 this-&gt;position_title = &quot;&quot;;
  46.                 this-&gt;duration = 0;
  47.                 this-&gt;location = &quot;&quot;;
  48.                 this-&gt;institution_name = &quot;&quot;;
  49.                 this-&gt;salary = 0;
  50.             }
  51.         
  52.         friend std::ostream&amp; operator&lt;&lt;(std::ostream&amp; os, const Experience&amp; e)
  53.             {
  54.                 os &lt;&lt; &quot;from_date: &quot; &lt;&lt; e.from_date &lt;&lt; std::endl;
  55.                 os &lt;&lt; &quot;to_date: &quot; &lt;&lt; e.to_date &lt;&lt; std::endl;
  56.                 os &lt;&lt; &quot;position_title: &quot; &lt;&lt; e.position_title &lt;&lt; std::endl;
  57.                 os &lt;&lt; &quot;duration: &quot; &lt;&lt; e.duration &lt;&lt; std::endl;
  58.                 os &lt;&lt; &quot;location: &quot; &lt;&lt; e.location &lt;&lt; std::endl;
  59.                 os &lt;&lt; &quot;institution_name: &quot; &lt;&lt; e.institution_name &lt;&lt; std::endl;
  60.                 os &lt;&lt; &quot;salary: &quot; &lt;&lt; e.salary &lt;&lt; std::endl;
  61.                 return os;
  62.             }
  64.     };
  65. typedef std::vector&lt;Experience&gt; Experiences;
  67. struct Profile
  68.     {
  69.         s linkedin_url;
  70.         s name;
  71.         Experiences experiences;
  72.         std::vector&lt;s&gt; skills;
  74.         Profile(s linkedin_url, s name, std::vector&lt;s&gt; skills, Experiences experiences)
  75.             {
  76.                 this-&gt;linkedin_url = linkedin_url;
  77.                 this-&gt;name = name;
  78.                 this-&gt;skills = skills;
  79.                 this-&gt;experiences = experiences;
  80.             }
  81.         
  82.         Profile()
  83.             {
  84.                 this-&gt;linkedin_url = &quot;&quot;;
  85.                 this-&gt;name = &quot;&quot;;
  86.                 this-&gt;skills = {};
  87.                 this-&gt;experiences = {};
  88.             }
  89.         
  90.         friend std::ostream&amp; operator&lt;&lt;(std::ostream&amp; os, const Profile&amp; p)
  91.             {
  92.                 os &lt;&lt; &quot;linkedin_url: &quot; &lt;&lt; p.linkedin_url &lt;&lt; std::endl;
  93.                 os &lt;&lt; &quot;name: &quot; &lt;&lt; p.name &lt;&lt; std::endl;
  94.                 os &lt;&lt; &quot;experiences: &quot; &lt;&lt; std::endl;
  95.                 for (auto e : p.experiences)
  96.                     {
  97.                         os &lt;&lt; &#39;\t&#39; &lt;&lt; e &lt;&lt; std::endl;
  98.                     }
  99.                 return os;
  100.             }
  101.     };
  103. typedef std::vector&lt;Profile&gt; Profiles;
  105. struct Node
  106.     {
  107.         s name;
  108.         s position_title;
  109.         s institution_name;
  110.         s location;
  111.         s industry;
  112.         s linkedin_url;
  113.         float duration;
  114.         int company_size;
  115.         float median_tenure;
  116.         float salary;
  117.         float headcount_growth;
  118.         float current_experience_duration;
  120.         Node(s t_name,s t_position_title, s t_institution_name, s t_location, s t_industry,s linkedin_url, float t_duration, float t_current_experience_duration, int t_company_size, float t_median_tenure, float t_salary, float t_headcount_growth )
  121.             {
  122.                 this-&gt;name = t_name;
  123.                 this-&gt;position_title = t_position_title;
  124.                 this-&gt;institution_name = t_institution_name;
  125.                 this-&gt;location = t_location;
  126.                 this-&gt;industry = t_industry;
  127.                 this-&gt;linkedin_url = linkedin_url;
  128.                 this-&gt;duration = t_duration;
  129.                 this-&gt;current_experience_duration = t_current_experience_duration;
  130.                 this-&gt;company_size = t_company_size;
  131.                 this-&gt;median_tenure = t_median_tenure;
  132.                 this-&gt;salary = t_salary;
  133.                 this-&gt;headcount_growth = t_headcount_growth;
  134.             }
  135.         
  136.         Node()
  137.             {
  138.                 this-&gt;name = &quot;&quot;;
  139.                 this-&gt;position_title = &quot;&quot;;
  140.                 this-&gt;institution_name = &quot;&quot;;
  141.                 this-&gt;location = &quot;&quot;;
  142.                 this-&gt;industry = &quot;&quot;;
  143.                 this-&gt;linkedin_url = &quot;&quot;;
  144.                 this-&gt;duration = 0;
  145.                 this-&gt;current_experience_duration = 0;
  146.                 this-&gt;company_size = 0;
  147.                 this-&gt;median_tenure = 0;
  148.                 this-&gt;salary = 0;
  149.                 this-&gt;headcount_growth = 0;
  150.             }
  152.         bool operator==(const Node&amp; other) const
  153.             {
  154.                 if (this-&gt;name == other.name &amp;&amp; this-&gt;position_title == other.position_title &amp;&amp; this-&gt;institution_name == other.institution_name &amp;&amp; this-&gt;location == other.location)
  155.                     return true;
  156.                 else
  157.                     return false;
  158.             }
  159.         
  160.         friend std::ostream&amp; operator&lt;&lt;(std::ostream&amp; os, const Node&amp; node)
  161.             {
  162.                 os &lt;&lt; &quot;Name: &quot; &lt;&lt; node.name &lt;&lt; std::endl;
  163.                 os &lt;&lt; &quot;Position Title: &quot; &lt;&lt; node.position_title &lt;&lt; std::endl;
  164.                 os &lt;&lt; &quot;Institution Name: &quot; &lt;&lt; node.institution_name &lt;&lt; std::endl;
  165.                 os &lt;&lt; &quot;Location: &quot; &lt;&lt; node.location &lt;&lt; std::endl;
  166.                 os &lt;&lt; &quot;Industry: &quot; &lt;&lt; node.industry &lt;&lt; std::endl;
  167.                 os &lt;&lt; &quot;Linkedin URL: &quot; &lt;&lt; node.linkedin_url &lt;&lt; std::endl;
  168.                 os &lt;&lt; &quot;Duration: &quot; &lt;&lt; node.duration &lt;&lt; std::endl;
  169.                 os &lt;&lt; &quot;Current Experience Duration &quot;&lt;&lt; node.current_experience_duration &lt;&lt; std::endl;
  170.                 os &lt;&lt; &quot;Company Size: &quot; &lt;&lt; node.company_size &lt;&lt; std::endl;
  171.                 os &lt;&lt; &quot;Median Tenure: &quot; &lt;&lt; node.median_tenure &lt;&lt; std::endl;
  172.                 os &lt;&lt; &quot;Salary: &quot; &lt;&lt; node.salary &lt;&lt; std::endl;
  173.                 os &lt;&lt; &quot;Headcount Growth: &quot; &lt;&lt; node.headcount_growth &lt;&lt; std::endl;
  174.                 return os;
  175.             }
  176.         
  177.     };
  179. typedef std::vector&lt;Node&gt; Nodes;
  182. struct Edge
  183.     {
  184.         Node source;
  185.         Node target;
  186.         s linkedin_url;
  187.         float duration;
  188.         int company_size;
  189.         float median_tenure;
  190.         float salary;
  191.         float headcount_growth;
  193.         Edge(Node t_source, Node t_target)
  194.             {
  195.                 
  196.                 this-&gt;source = t_source;
  197.                 this-&gt;target = t_target;
  198.                 this-&gt;linkedin_url = this-&gt;target.linkedin_url;
  199.                 this-&gt;duration = this-&gt;target.duration;
  200.                 this-&gt;company_size = this-&gt;target.company_size;
  201.                 this-&gt;median_tenure = this-&gt;target.median_tenure;
  202.                 this-&gt;salary = this-&gt;target.salary;
  203.                 this-&gt;headcount_growth = this-&gt;target.headcount_growth;
  204.             }
  205.         
  206.         Edge()
  207.             {
  208.                 this-&gt;source = Node();
  209.                 this-&gt;target = Node();
  210.                 this-&gt;linkedin_url = &quot;&quot;;
  211.                 this-&gt;duration = 0;
  212.                 this-&gt;company_size = 0;
  213.                 this-&gt;median_tenure = 0;
  214.                 this-&gt;salary = 0;
  215.                 this-&gt;headcount_growth = 0;
  216.             }
  217.         
  218.         bool operator==(const Edge&amp; other) const
  219.             {
  220.                 if (this-&gt;source == other.source &amp;&amp; this-&gt;target == other.target)
  221.                     return true;
  222.                 else
  223.                     return false;
  224.             }
  225.         
  226.         friend std::ostream&amp; operator&lt;&lt;(std::ostream&amp; os, const Edge&amp; edge)
  227.             {
  228.                 os &lt;&lt; &quot;Source: &quot; &lt;&lt; edge.source &lt;&lt; std::endl;
  229.                 os &lt;&lt; &quot;Target: &quot; &lt;&lt; edge.target &lt;&lt; std::endl;
  230.                 os &lt;&lt; &quot;Linkedin URL: &quot; &lt;&lt; edge.linkedin_url &lt;&lt; std::endl;
  231.                 os &lt;&lt; &quot;Duration: &quot; &lt;&lt; edge.duration &lt;&lt; std::endl;
  232.                 os &lt;&lt; &quot;Company Size: &quot; &lt;&lt; edge.company_size &lt;&lt; std::endl;
  233.                 os &lt;&lt; &quot;Median Tenure: &quot; &lt;&lt; edge.median_tenure &lt;&lt; std::endl;
  234.                 os &lt;&lt; &quot;Salary: &quot; &lt;&lt; edge.salary &lt;&lt; std::endl;
  235.                 os &lt;&lt; &quot;Headcount Growth: &quot; &lt;&lt; edge.headcount_growth &lt;&lt; std::endl;
  236.                 return os;
  237.             }
  238.     };
  241. typedef std::vector&lt;Edge&gt; Edges;
  244. struct Company
  245.     {
  246.         s name;
  247.         s industry;
  248.         float headcount_growth;
  249.         float median_tenure;
  250.         int company_size;
  252.         Company(s name, s industry, float headcount_growth, float median_tenure, int company_size)
  253.             {
  254.                 this-&gt;name = name;
  255.                 this-&gt;industry = industry;
  256.                 this-&gt;headcount_growth = headcount_growth;
  257.                 this-&gt;median_tenure = median_tenure;
  258.                 this-&gt;company_size = company_size;
  259.             }
  260.         
  261.         Company()
  262.             {
  263.                 this-&gt;name = &quot;&quot;;
  264.                 this-&gt;industry = &quot;&quot;;
  265.                 this-&gt;headcount_growth = 0;
  266.                 this-&gt;median_tenure = 0;
  267.                 this-&gt;company_size = 0;
  268.             }
  269.         
  270.         bool operator==(const Company&amp; other) const
  271.             {
  272.                 if (this-&gt;name == other.name)
  273.                     {
  274.                         return true;
  275.                     }
  276.                 else
  277.                     {
  278.                         return false;
  279.                     }
  280.             }
  281.         
  282.         friend std::ostream&amp; operator&lt;&lt;(std::ostream&amp; os, const Company&amp; company)
  283.             {
  284.                 os &lt;&lt; &quot;Name: &quot; &lt;&lt; company.name &lt;&lt; std::endl;
  285.                 os &lt;&lt; &quot;Industry: &quot; &lt;&lt; company.industry &lt;&lt; std::endl;
  286.                 os &lt;&lt; &quot;Headcount Growth: &quot; &lt;&lt; company.headcount_growth &lt;&lt; std::endl;
  287.                 os &lt;&lt; &quot;Median Tenure: &quot; &lt;&lt; company.median_tenure &lt;&lt; std::endl;
  288.                 os &lt;&lt; &quot;Company Size: &quot; &lt;&lt; company.company_size &lt;&lt; std::endl;
  289.                 return os;
  290.             }
  292.     };
  294. typedef std::vector&lt;Company&gt; Companies;
  296. #endif // DEFINITIONS_H

The profiles.h source file (have not included irrelevant code):

  1. #ifndef PROFILES_H
  2. #define PROFILES_H
  4. #include &quot;definitions.h&quot;
  6. std::pair&lt;Nodes,Edges&gt; create_edges_and_nodes_from_profiles(Profiles &amp; profiles, Companies &amp; companies );
  8. #endif // PROFILES_H

The profiles.cpp file:

  1. std::pair&lt;Nodes,Edges&gt; create_edges_and_nodes_from_profiles(Profiles &amp; profiles, Companies &amp; companies)
  2.     {
  3.         using namespace std::literals;
  5.         Nodes nodes;
  6.         Edges edges;
  7.         nodes.reserve(40&#39;000);
  8.         edges.reserve(40&#39;000);
  10.         bool use_profile;
  13.         std::unordered_map&lt;s,float&gt; company_name_median_tenure_map;
  14.         std::unordered_map&lt;s,float&gt; company_name_headcount_growth_map;
  15.         std::unordered_map&lt;s,int&gt; company_name_company_size_map;
  16.         std::unordered_map&lt;s,s&gt; company_name_industry_map;
  18.         float current_duration;
  19.         float t_company_size, t_median_tenure, t_headcount_growth, t_duration, t_salary;
  20.         s t_name, t_position_title, t_location, t_institution_name, t_industry;
  22.         
  24.         #ifdef MONITOR
  25.             auto before_map_createion = std::chrono::high_resolution_clock::now();
  26.         #endif  
  28.         for (Company &amp; company : companies)
  29.             {
  30.                 
  31.                 company_name_median_tenure_map[company.name] = company.median_tenure;
  32.                 company_name_headcount_growth_map[company.name] = company.headcount_growth;
  33.                 company_name_company_size_map[company.name] = company.company_size;
  34.                 company_name_industry_map[company.name] = company.industry;
  36.             }
  37.         
  38.         #ifdef MONITOR
  39.             auto after_map_creation = std::chrono::high_resolution_clock::now();
  41.             auto temp = std::chrono::duration_cast&lt;std::chrono::milliseconds&gt;(after_map_creation-before_map_createion).count();
  43.             std::cout&lt;&lt;temp&lt;&lt;std::endl;
  44.         #endif
  46.         for (Profile &amp; profile : profiles)
  47.             {
  48.                 Nodes nodes_temp;
  49.                 nodes_temp.reserve(profile.experiences.size());
  50.                 current_duration = 0.0;
  51.                 use_profile = false;
  54.                 for (Experience &amp; experience : profile.experiences)
  55.                     {
  56.                         
  57.                         stv location = stv(experience.location);
  58.                         
  59.                         if (location.compare(&quot;&quot;sv)!=0)
  60.                             {
  61.                                 
  62.                                 //if (location.find(&quot;United Kingdom&quot;sv)!=stv::npos)
  63.                                     
  64.                                 t_name = profile.name;
  65.                                 t_position_title = experience.position_title;
  66.                                 t_location = experience.location;
  68.                                 
  69.                                 t_duration = experience.duration;
  70.                                 
  71.                                 
  72.                                 t_institution_name = experience.institution_name;
  73.                                 
  74.                                 t_company_size = company_name_company_size_map[t_institution_name];
  75.                                 t_median_tenure = company_name_median_tenure_map[t_institution_name];
  76.                                 t_headcount_growth = company_name_headcount_growth_map[t_institution_name];
  78.                                 
  79.                                 t_salary = experience.salary;
  82.                                 t_industry = company_name_industry_map[t_institution_name];
  83.                                 
  84.                                 Node node_obj = Node(std::move(t_name),
  85.                                     std::move(t_position_title),
  86.                                         std::move(t_institution_name),
  87.                                             std::move(t_location),
  88.                                                 std::move(t_industry),
  89.                                                     profile.linkedin_url,
  90.                                                         t_duration,
  91.                                                             current_duration,
  92.                                                                 t_company_size,
  93.                                                                     t_median_tenure,
  94.                                                                         t_salary,
  95.                                                                             t_headcount_growth);
  96.                                                         
  97.                                 
  98.                                 nodes_temp.push_back(std::move(node_obj));
  99.                                 
  100.                                 current_duration += t_duration;
  101.                                     
  102.                             }
  103.                         
  104.                     }
  105.                 
  106.                 for (Node &amp; node : nodes_temp)
  107.                     {
  108.                         if (node.location.compare(&quot;&quot;sv)!=0)
  109.                         {
  110.                             use_profile = true;
  111.                             break;
  112.                         }
  113.                             
  114.                     }
  115.                 
  116.                 if (!use_profile)
  117.                     continue;
  118.                 
  119.                 current_duration = 0.0;
  121.                 for (Nodes::reverse_iterator rit=nodes_temp.rbegin();rit!=nodes_temp.rend();++rit)
  122.                     {
  123.                         rit-&gt;current_experience_duration = current_duration;
  124.                         current_duration += rit-&gt;duration;
  125.                     }
  126.                 
  127.                 if (nodes_temp.size()&gt;1)
  128.                     {
  129.                         for (int i=0;i&lt;nodes_temp.size()-1;i++)
  130.                             {
  131.                                 //Edge edge = Edge(&amp;nodes_temp[i+1],&amp;nodes_temp[i]);
  132.                                 edges.emplace_back(std::move(nodes_temp[i+1]),std::move(nodes_temp[i]));
  134.                             }
  135.                     }
  136.                 
  137.                 for (auto &amp; node : nodes_temp)
  138.                     {
  139.                         nodes.push_back(std::move(node));
  140.                     }
  141.             }
  143.         return std::make_pair(std::move(nodes),std::move(edges));
  144.     }

Now in my main driver:

  1. #include &quot;definitions.h&quot;
  2. #include &quot;profiles.h&quot;
  5. int main()
  6.   {
  7.      // not shown (but assume this works and created the profile objects as shown in definitions.h)
  8.      Profiles profiles = get_profiles(coll_profiles);
  9.     // Make the same assumption as before 
  10.      Companies companies = get_companies(coll_companies);
  12.       #ifdef MONITOR
  13.             
  14.           auto before_creating_edges_and_nodes =  std::chrono::high_resolution_clock::now();
  15.             
  16.       #endif
  18.         
  19.         
  20.       // Create nodes and edges from profiles and companies
  21.       auto[nodes, edges] =  create_edges_and_nodes_from_profiles(profiles,companies);
  23.       #ifdef MONITOR
  24.           auto after_creating_edges_and_nodes =  std::chrono::high_resolution_clock::now();
  25.           auto time_creating_edges_and_nodes = std::chrono::duration_cast&lt;std::chrono::milliseconds&gt;(after_creating_edges_and_nodes - before_creating_edges_and_nodes).count();
  27.             
  28.       #endif
  29.       // lots of functions using Nodes and Edges 
  30.       //...
  31.       //...
  32.       return 0;
  33.   }

Note that I am not an expert in C++. The code shown above works but it takes a significant amount of time (~150 milliseconds). The rest of the script combined (around 15 functions) takes less than 100 milliseconds.

My question is basically, how do I restructure the data and/or the initialization of the objects so that it is as fast as possible.

The reason I am asking is because, I found it impossible to find how to do this on Google. It could be because I don't know the right terminology.

答案1

得分: 1

Replace

  1. std::unordered_map<s,float> company_name_median_tenure_map;
  2. std::unordered_map<s,float> company_name_headcount_growth_map;
  3. std::unordered_map<s,int> company_name_company_size_map;
  4. std::unordered_map<s,s> company_name_industry_map;

with

  1. struct company_data
  2. {
  3.     float tenure;
  4.     float growth;
  5.     int size;
  6.     std::string industry;      // this should be an index into a table of industry names
  7. };
  9. std::unordered_map<std::string,company_data> company_map;
英文:

Replace

  1.     std::unordered_map&lt;s,float&gt; company_name_median_tenure_map;
  2. std::unordered_map&lt;s,float&gt; company_name_headcount_growth_map;
  3. std::unordered_map&lt;s,int&gt; company_name_company_size_map;
  4. std::unordered_map&lt;s,s&gt; company_name_industry_map;

with

  1. struct company_data
  2. {
  3. float tenure;
  4. float growth;
  5. int size
  6. std:string industry;      // this should be an index into a table of industry names
  7. };
  8. std::unordered_map&lt;std::string,company_data&gt;  company_map;

huangapple
  • 本文由 发表于 2023年6月25日 20:09:05
  • 转载请务必保留本文链接：https://go.coder-hub.com/76550312-2.html
  • c++
  • graph-theory
  • performance
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