侯捷STL学习(二)--序列容器测试

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mob604756eb17db 2017-06-04 23:57:00

文章标签 侯捷STL #include ios c++ map容器 文章分类 代码人生

第六节：容器之分类和各种测试（四）

stack不提供iterator操作，破坏了容器的独特性，先进先出。

使用容器multiset（允许元素重复）

内部是红黑树，insert操作就保证了排好了序。
标准库有个：：find()函数，大家都可以用。容器本身也有一个c.find()，通过键值对查找非常快！
测试

#include <set>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj06
{
void test_multiset(long& value)
{
    cout << "\ntest_multiset().......... \n";
    
multiset<string> c;     
char buf[10];       
clock_t timeStart = clock();                                
    for(long i=0; i< value; ++i)
    {
        try {
            snprintf(buf, 10, "%d", rand());
            c.insert(string(buf));                  
        }
        catch(exception& p) {
            cout << "i=" << i << " " << p.what() << endl;   
            abort();
        }
    }
    cout << "milli-seconds : " << (clock()-timeStart) << endl;  
    cout << "multiset.size()= " << c.size() << endl;    
    cout << "multiset.max_size()= " << c.max_size() << endl;    //214748364
    
string target = get_a_target_string();  
    {
    timeStart = clock();
auto pItem = find(c.begin(), c.end(), target);  //比 c.find(...) 慢很多 
    cout << "std::find(), milli-seconds : " << (clock()-timeStart) << endl;     
    if (pItem != c.end())
        cout << "found, " << *pItem << endl;
    else
        cout << "not found! " << endl;  
    }
    
    {
    timeStart = clock();        
auto pItem = c.find(target);        //比 std::find(...) 快很多                          
    cout << "c.find(), milli-seconds : " << (clock()-timeStart) << endl;         
    if (pItem != c.end())
        cout << "found, " << *pItem << endl;
    else
        cout << "not found! " << endl;  
    }   
     
    c.clear();
    test_moveable(multiset<MyString>(),multiset<MyStrNoMove>(), value);                         
}                                                            
}

使用容器multimap（允许元素重复）

内部是红黑树，key-value键值对。
multiset不可用[]做insertion
c.insert(pair<long,string>(i,buff))
(*pItem).second
测试

#include <map>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj07
{
void test_multimap(long& value)
{
    cout << "\ntest_multimap().......... \n";
     
multimap<long, string> c;   
char buf[10];
            
clock_t timeStart = clock();                                
    for(long i=0; i< value; ++i)
    {
        try {
            snprintf(buf, 10, "%d", rand());
            //multimap 不可使用 [] 做 insertion 
            c.insert(pair<long,string>(i,buf));                         
        }
        catch(exception& p) {
            cout << "i=" << i << " " << p.what() << endl;   
            abort();
        }
    }
    cout << "milli-seconds : " << (clock()-timeStart) << endl;  
    cout << "multimap.size()= " << c.size() << endl;
    cout << "multimap.max_size()= " << c.max_size() << endl;    //178956970 
    
long target = get_a_target_long();      
    timeStart = clock();        
auto pItem = c.find(target);                                
    cout << "c.find(), milli-seconds : " << (clock()-timeStart) << endl;     
    if (pItem != c.end())
        cout << "found, value=" << (*pItem).second << endl;
    else
        cout << "not found! " << endl;    
        
    c.clear();                          
}                                                            
}

使用unordered_multiset容器

使用hashtable使用分离链地址方法实现
gnu C之前的名称hash_multiset
unorder_multiset.bucket_count篮子的个数
load_factor,max_load_factor,max_bucket_count方法
篮子后面的链表不能太长，元素的个数大于等于篮子的个数，就需要重新分配篮子的大小，重新进行插入元素
c.find()容器自身的find操作快很多
测试

#include <unordered_set>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj08
{
void test_unordered_multiset(long& value)
{
    cout << "\ntest_unordered_multiset().......... \n";
     
unordered_multiset<string> c;   
char buf[10];
            
clock_t timeStart = clock();                                
    for(long i=0; i< value; ++i)
    {
        try {
            snprintf(buf, 10, "%d", rand());
            c.insert(string(buf));                      
        }
        catch(exception& p) {
            cout << "i=" << i << " " << p.what() << endl;   
            abort();
        }
    }
    cout << "milli-seconds : " << (clock()-timeStart) << endl;      
    cout << "unordered_multiset.size()= " << c.size() << endl;
    cout << "unordered_multiset.max_size()= " << c.max_size() << endl;  //357913941
    cout << "unordered_multiset.bucket_count()= " << c.bucket_count() << endl;  
    cout << "unordered_multiset.load_factor()= " << c.load_factor() << endl;    
    cout << "unordered_multiset.max_load_factor()= " << c.max_load_factor() << endl;    
    cout << "unordered_multiset.max_bucket_count()= " << c.max_bucket_count() << endl;              
    for (unsigned i=0; i< 20; ++i) {
        cout << "bucket #" << i << " has " << c.bucket_size(i) << " elements.\n";
    }                   
                
string target = get_a_target_string();  
    {
    timeStart = clock();
auto pItem = find(c.begin(), c.end(), target);  //比 c.find(...) 慢很多 
    cout << "std::find(), milli-seconds : " << (clock()-timeStart) << endl; 
    if (pItem != c.end())
        cout << "found, " << *pItem << endl;
    else
        cout << "not found! " << endl;  
    }
 
    {
    timeStart = clock();        
auto pItem = c.find(target);        //比 std::find(...) 快很多                          
    cout << "c.find(), milli-seconds : " << (clock()-timeStart) << endl;     
    if (pItem != c.end())
        cout << "found, " << *pItem << endl;
    else
        cout << "not found! " << endl;  
    }       
     
    c.clear();
    test_moveable(unordered_multiset<MyString>(),unordered_multiset<MyStrNoMove>(), value);                                     
}                                                    
}

使用unordered_multimap容器

测试

#include <unordered_map>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj09
{
void test_unordered_multimap(long& value)
{
    cout << "\ntest_unordered_multimap().......... \n";
     
unordered_multimap<long, string> c;     
char buf[10];
            
clock_t timeStart = clock();                                
    for(long i=0; i< value; ++i)
    {
        try {
            snprintf(buf, 10, "%d", rand());
            //multimap 不可使用 [] 進行 insertion 
            c.insert(pair<long,string>(i,buf));
        }
        catch(exception& p) {
            cout << "i=" << i << " " << p.what() << endl;   
            abort();
        }
    }
    cout << "milli-seconds : " << (clock()-timeStart) << endl;      
    cout << "unordered_multimap.size()= " << c.size() << endl;  
    cout << "unordered_multimap.max_size()= " << c.max_size() << endl;  //357913941 
    
long target = get_a_target_long();      
    timeStart = clock();        
auto pItem = c.find(target);                                
    cout << "c.find(), milli-seconds : " << (clock()-timeStart) << endl;         
    if (pItem != c.end())
        cout << "found, value=" << (*pItem).second << endl;
    else
        cout << "not found! " << endl;      
}                                                            
}

使用set容器

不允许元素重复

#include <set>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj13
{
void test_set(long& value)
{
    cout << "\ntest_set().......... \n";
     
set<string> c;      
char buf[10];

clock_t timeStart = clock();                                
    for(long i=0; i< value; ++i)
    {
        try {
            snprintf(buf, 10, "%d", rand());
            c.insert(string(buf));                      
        }
        catch(exception& p) {
            cout << "i=" << i << " " << p.what() << endl;   
            abort();
        }
    }
    cout << "milli-seconds : " << (clock()-timeStart) << endl;      
    cout << "set.size()= " << c.size() << endl;
    cout << "set.max_size()= " << c.max_size() << endl;    //214748364
        
string target = get_a_target_string();  
    {
    timeStart = clock();
auto pItem = find(c.begin(), c.end(), target);  //比 c.find(...) 慢很多 
    cout << "std::find(), milli-seconds : " << (clock()-timeStart) << endl;     
    if (pItem != c.end())
        cout << "found, " << *pItem << endl;
    else
        cout << "not found! " << endl;  
    }
    
    {
    timeStart = clock();        
auto pItem = c.find(target);        //比 std::find(...) 快很多                          
    cout << "c.find(), milli-seconds : " << (clock()-timeStart) << endl;         
    if (pItem != c.end())
        cout << "found, " << *pItem << endl;
    else
        cout << "not found! " << endl;  
    }                           
}                                                            
}

使用map容器

不允许元素键重复
c[i]=string(buf)组成pair，允许这样进行插入操作

#include <map>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj14
{
void test_map(long& value)
{
    cout << "\ntest_map().......... \n";
     
map<long, string> c;    
char buf[10];
            
clock_t timeStart = clock();                                
    for(long i=0; i< value; ++i)
    {
        try {
            snprintf(buf, 10, "%d", rand());
            c[i] = string(buf);                     
        }
        catch(exception& p) {
            cout << "i=" << i << " " << p.what() << endl;   
            abort();
        }
    }
    cout << "milli-seconds : " << (clock()-timeStart) << endl;  
    cout << "map.size()= " << c.size() << endl; 
    cout << "map.max_size()= " << c.max_size() << endl;     //178956970
    
long target = get_a_target_long();      
    timeStart = clock();        
auto pItem = c.find(target);                                
    cout << "c.find(), milli-seconds : " << (clock()-timeStart) << endl;         
    if (pItem != c.end())
        cout << "found, value=" << (*pItem).second << endl;
    else
        cout << "not found! " << endl;          
        
    c.clear();                  
}                                                            
}

使用unorder_set容器

#include <unordered_set>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj15
{
void test_unordered_set(long& value)
{
    cout << "\ntest_unordered_set().......... \n";
     
unordered_set<string> c;    
char buf[10];
            
clock_t timeStart = clock();                                
    for(long i=0; i< value; ++i)
    {
        try {
            snprintf(buf, 10, "%d", rand());
            c.insert(string(buf));                      
        }
        catch(exception& p) {
            cout << "i=" << i << " " << p.what() << endl;   
            abort();
        }
    }
    cout << "milli-seconds : " << (clock()-timeStart) << endl;      
    cout << "unordered_set.size()= " << c.size() << endl;   
    cout << "unordered_set.max_size()= " << c.max_size() << endl;  //357913941
    cout << "unordered_set.bucket_count()= " << c.bucket_count() << endl;   
    cout << "unordered_set.load_factor()= " << c.load_factor() << endl; 
    cout << "unordered_set.max_load_factor()= " << c.max_load_factor() << endl; 
    cout << "unordered_set.max_bucket_count()= " << c.max_bucket_count() << endl;           
    for (unsigned i=0; i< 20; ++i) {
        cout << "bucket #" << i << " has " << c.bucket_size(i) << " elements.\n";
    }           
    
string target = get_a_target_string();  
    {
    timeStart = clock();
auto pItem = find(c.begin(), c.end(), target);  //比 c.find(...) 慢很多 
    cout << "std::find(), milli-seconds : " << (clock()-timeStart) << endl;     
    if (pItem != c.end())
        cout << "found, " << *pItem << endl;
    else
        cout << "not found! " << endl;  
    }
 
    {
    timeStart = clock();        
auto pItem = c.find(target);        //比 std::find(...) 快很多                          
    cout << "c.find(), milli-seconds : " << (clock()-timeStart) << endl;         
    if (pItem != c.end())
        cout << "found, " << *pItem << endl;
    else
        cout << "not found! " << endl;  
    }   
}                                                            
}

使用unorder_map容器

#include <unordered_map>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj16
{
void test_unordered_map(long& value)
{
    cout << "\ntest_unordered_map().......... \n";

unordered_map<long, string> c;      
char buf[10];
            
clock_t timeStart = clock();                                
    for(long i=0; i< value; ++i)
    {
        try {
            snprintf(buf, 10, "%d", rand());
            c[i] = string(buf);         
        }
        catch(exception& p) {
            cout << "i=" << i << " " << p.what() << endl;   
            abort();
        }
    }
    cout << "milli-seconds : " << (clock()-timeStart) << endl;      
    cout << "unordered_map.size()= " << c.size() << endl;   //357913941
    cout << "unordered_map.max_size()= " << c.max_size() << endl;   
    
long target = get_a_target_long();      
    timeStart = clock();    
//! auto pItem = find(c.begin(), c.end(), target);  //map 不適用 std::find()           
auto pItem = c.find(target);
                        
    cout << "c.find(), milli-seconds : " << (clock()-timeStart) << endl;         
    if (pItem != c.end())
        cout << "found, value=" << (*pItem).second << endl;
    else
        cout << "not found! " << endl;      
}                                                            
}

hash_set/hash_map/hash_multiset/hash_multimap

包含gnu C的编译器就可以
包含的头文件可能需要修改#include<...>非标准容器，由于时间的原因，没有放在一起,在C++11大会之前就出现了！
测试

/*
以下測試 hash_multiset, hash_multimap 過程中遇到阻礙：
headers <hash_set> 和 <hash_map> 各有兩個，
分別在 ...\4.9.2\include\c++\backward 和 ...\4.9.2\include\c++\ext，
不知要用哪一組! 
用 <ext\...> 那一組會有問題 
   ...\4.9.2\include\c++\backward\hashtable.h 
   [Error] no match for call to '(const hasher {aka const __gnu_cxx::hash<std::basic_string<char> >}) (const key_type&)'
用 <backward\...> 那一組有相同的問題.  
so, 放棄測試 (no insertion or push_back or ...).  
*/

#include <ext\hash_set>    
    //...\4.9.2\include\c++\backward\backward_warning.h  
   //[Warning] #warning This file includes at least one deprecated or antiquated header 
   //which may be removed without further notice at a future date. 
   //Please use a non-deprecated interface with equivalent functionality instead. 
   //For a listing of replacement headers and interfaces, consult the file backward_warning.h. 
   //To disable this warning use -Wno-deprecated. [-Wcpp]
   
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj11
{
void test_hash_multiset(long& value)
{
   cout << "\ntest_hash_multiset().......... \n";
   
   __gnu_cxx::hash_multiset<string> c;    
   char buf[10];
         
    clock_t timeStart = clock();                      
    for(long i=0; i< value; ++i)
    {
      try {
         snprintf(buf, 10, "%d", rand());
         //! c.insert(string(buf));          
      }
      catch(exception& p) {
         cout << "i=" << i << " " << p.what() << endl;   
         abort();
      }
   }
   cout << "milli-seconds : " << (clock()-timeStart) << endl;           
}                                             
}
//---------------------------------------------------
#include <ext\hash_map>
    //...\4.9.2\include\c++\backward\backward_warning.h  
   //[Warning] #warning This file ... (如上個函數所言)
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj12
{
void test_hash_multimap(long& value)
{
   cout << "\ntest_hash_multimap().......... \n";
     
   __gnu_cxx::hash_multimap<long, string> c;    
   char buf[10];
         
    clock_t timeStart = clock();                      
    for(long i=0; i< value; ++i)
    {
      try {
         snprintf(buf, 10, "%d", rand());
         //c.insert(...       
      }
      catch(exception& p) {
         cout << "i=" << i << " " << p.what() << endl;   
         abort();
      }
   }
   cout << "milli-seconds : " << (clock()-timeStart) << endl;     
   
    timeStart = clock();                        
    //! auto ite = c.find(...
   cout << "milli-seconds : " << (clock()-timeStart) << endl;     
}                                   
}

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侯捷STL学习(二)--序列容器测试

侯捷STL学习(二)--序列容器测试

第六节：容器之分类和各种测试（四）

使用容器multiset（允许元素重复）

使用容器multimap（允许元素重复）

使用unordered_multiset容器

使用unordered_multimap容器

使用set容器

使用map容器

使用unorder_set容器

使用unorder_map容器

hash_set/hash_map/hash_multiset/hash_multimap

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