C++——容器之分类与各种测试

Posted 2023-03-31 Strive_LiJiaLe

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文章目录

六大部件的关系
容器——结构与分类

六大部件的关系

容器——结构与分类

set与multiset的区别：set中的key值(key就是value)不可以重复，而multiset可以重复。
实现底层是红黑树，保持高度平衡的二叉树。自动调整

sequence 容器

使用容器array——代码案例

#include <array>
#include <iostream>
#include <ctime> 
#include <cstdlib> //qsort, bsearch, NULL

namespace jj01

void test_array()

	cout << "\\ntest_array().......... \\n";
     
array<long,ASIZE> c;  	
			
clock_t timeStart = clock();									
    for(long i=0; i< ASIZE; ++i) 
        c[i] = rand(); 
    
	cout << "milli-seconds : " << (clock()-timeStart) << endl;	//
	cout << "array.size()= " << c.size() << endl;		
	cout << "array.front()= " << c.front() << endl;	
	cout << "array.back()= " << c.back() << endl;	
	cout << "array.data()= " << c.data() << endl;	//array.data() ：起始位地址
	
long target = get_a_target_long();//输入要寻找的目标

	timeStart = clock();//该函数从运行开始到该指令的毫妙数
    ::qsort(c.data(), ASIZE, sizeof(long), compareLongs);//qsort()：1.起始位地址；2.元素个数；3.类型大小；4.比较函数（策略）
long* pItem = (long*)::bsearch(&target, (c.data()), ASIZE, sizeof(long), compareLongs); 
	cout << "qsort()+bsearch(), milli-seconds : " << (clock()-timeStart) << endl;	//先排序，再二分查找    
  	if (pItem != NULL)
    	cout << "found, " << *pItem << endl;
  	else
    	cout << "not found! " << endl;

long get_a_target_long()

long target=0;

	cout << "target (0~" << RAND_MAX << "): ";
	cin >> target;
	return target;

使用容器vector——代码案例

#include <vector>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
#include <algorithm> 	//sort()
namespace jj02

void test_vector(long& value)//传过来元素个数

	cout << "\\ntest_vector().......... \\n";
     
vector<string> c;  	
char buf[10];
			
clock_t timeStart = clock();								
    for(long i=0; i< value; ++i)
    
    	try 
    		snprintf(buf, 10, "%d", rand());
        	c.push_back(string(buf)); //尾部插入，双倍增长    		
		
		catch(exception& p) 
			cout << "i=" << i << " " << p.what() << endl;	
			     //曾經最高 i=58389486 then std::bad_alloc，内存不够
			abort();
		
	
	cout << "milli-seconds : " << (clock()-timeStart) << endl;	
	cout << "vector.max_size()= " << c.max_size() << endl;	//1073747823
	cout << "vector.size()= " << c.size() << endl;		
	cout << "vector.front()= " << c.front() << endl;	
	cout << "vector.back()= " << c.back() << endl;	
	cout << "vector.data()= " << c.data() << endl;
	cout << "vector.capacity()= " << c.capacity() << endl << endl;		

																				
string target = get_a_target_string();
    
	timeStart = clock();
auto pItem = find(c.begin(), c.end(), target);
	cout << "std::find(), milli-seconds : " << (clock()-timeStart) << endl;  
	 
  	if (pItem != c.end())
    	cout << "found, " << *pItem << endl << endl;
  	else
    	cout << "not found! " << endl << endl;
    

	
	timeStart = clock();
    sort(c.begin(), c.end());
	cout << "sort(), milli-seconds : " << (clock()-timeStart) << endl; 
	
	timeStart = clock();	    
string* pItem = (string*)::bsearch(&target, (c.data()), 
                                   c.size(), sizeof(string), compareStrings); 
	cout << "bsearch(), milli-seconds : " << (clock()-timeStart) << endl; 
	   
  	if (pItem != NULL)
    	cout << "found, " << *pItem << endl << endl;
  	else
    	cout << "not found! " << endl << endl;	
	
	
	c.clear();
	test_moveable(vector<MyString>(),vector<MyStrNoMove>(), value);

使用容器list——代码案例

#include <list>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <algorithm> //find()
#include <iostream>
#include <ctime> 
namespace jj03

void test_list(long& value)

	cout << "\\ntest_list().......... \\n";
     
list<string> c;  	
char buf[10];
			
clock_t timeStart = clock();							
    for(long i=0; i< value; ++i)
    
    	try 
    		snprintf(buf, 10, "%d", rand());
        	c.push_back(string(buf));    	
		
		catch(exception& p) 
			cout << "i=" << i << " " << p.what() << endl;	
			abort();
		
	
	cout << "milli-seconds : " << (clock()-timeStart) << endl;		
	cout << "list.size()= " << c.size() << endl;
	cout << "list.max_size()= " << c.max_size() << endl;    //357913941
	cout << "list.front()= " << c.front() << endl;	
	cout << "list.back()= " << c.back() << endl;		
		
string target = get_a_target_string();		
    timeStart = clock();		
auto pItem = find(c.begin(), c.end(), target);						
	cout << "std::find(), milli-seconds : " << (clock()-timeStart) << endl;		
	
  	if (pItem != c.end())
    	cout << "found, " << *pItem << endl;
  	else
    	cout << "not found! " << endl;	
    	
    timeStart = clock();		
	c.sort();						
	cout << "c.sort(), milli-seconds : " << (clock()-timeStart) << endl;		    	
    	
	c.clear();
	test_moveable(list<MyString>(),list<MyStrNoMove>(), value);

使用容器forward list——代码案例

#include <forward_list>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj04

void test_forward_list(long& value)

	cout << "\\ntest_forward_list().......... \\n";
     
forward_list<string> c;  	
char buf[10];
			
clock_t timeStart = clock();								
    for(long i=0; i< value; ++i)
    
    	try 
    		snprintf(buf, 10, "%d", rand());
        	c.push_front(string(buf));  			   		
		
		catch(exception& p) 
			cout << "i=" << i << " " << p.what() << endl;	
			abort();
		
	
	cout << "milli-seconds : " << (clock()-timeStart) << endl;	
	cout << "forward_list.max_size()= " << c.max_size() << endl;  //536870911
	cout << "forward_list.front()= " << c.front() << endl;	


string target = get_a_target_string();	
    timeStart = clock();			
auto pItem = find(c.begin(), c.end(), target);	
	cout << "std::find(), milli-seconds : " << (clock()-timeStart) << endl;		
	
	if (pItem != c.end())
    	cout << "found, " << *pItem << endl;
  	else
    	cout << "not found! " << endl;	
    	
    timeStart = clock();		
	c.sort();						
	cout << "c.sort(), milli-seconds : " << (clock()-timeStart) << endl;		
	
	c.clear();

使用容器deque——代码案例

分段连续——由内部连续的段组成。前后都可再次扩充段。

#include <deque>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj05

void test_deque(long& value)

	cout << "\\ntest_deque().......... \\n";
     
deque<string> c;  	
char buf[10];
			
clock_t timeStart = clock();								
    for(long i=0; i< value; ++i)
    
    	try 
    		snprintf(buf, 10, "%d", rand());
        	c.push_back(string(buf));    			 		
		
		catch(exception& p) 
			cout << "i=" << i << " " << p.what() << endl;	
			abort();
		
	
	cout << "milli-seconds : " << (clock()-timeStart) << endl;		
	cout << "deque.size()= " << c.size() << endl;
	cout << "deque.front()= " << c.front() << endl;	
	cout << "deque.back()= " << c.back() << endl;	
	cout << "deque.max_size()= " << c.max_size() << endl;	//1073741821	
	
string target = get_a_target_string();	
    timeStart = clock();			
auto pItem = find(c.begin(), c.end(), target);	
	cout << "std::find(), milli-seconds : " << (clock()-timeStart) << endl;	
	
	if (pItem != c.end())
    	cout << "found, " << *pItem << endl;
  	else
    	cout << "not found! " << endl;	
    	
    timeStart = clock();		
	sort(c.begin(), c.end());						
	cout << "sort(), milli-seconds : " << (clock()-timeStart) << endl;		
	
	c.clear();
	test_moveable(deque<MyString>(),deque<MyStrNoMove>(), value);

关联式容器

使用容器multiset——代码案例

#include <set>
#include <stdexcept>
#include <string>
#include <cstdlib> //abort()
#include <cstdio>  //snprintf()
#include <iostream>
#include <ctime> 
namespace jj06

void test_multiset(long容器之分类与各种测试——set

set和multiset的去别在于前者的key值不可以重复，所以用随机数作为其元素进行插入时，遇到重复元素就会被拒绝插入（但是程序不会崩溃）。

 
 例程

#include<stdexcept>
#include<string>
#include<cstdlib>
#include<cstdio>
#include<algorithm>
#include<iostream>
#include<ctime>
#include<set>
using namespace std;
long get_a_target_long()
{
	long target = 0;
	cout<<"target(0~"<<RAND_MAX<<"):";
	cin>>target;
	return target;
}
string get_a_target_string()
{
	long target = 0;
	char buf[10];
	cout<<"target(0~"<<RAND_MAX<<"):";
	cin>>target;
	snprintf(buf, 10, "%ld", target);
	return string(buf);
}
int compareLongs(const void* a, const void* b)
{
	return (*(long*)a - *(long*)b);
}

int compareStrings(const void *a, const void *b)
{
	if(*(string*)a > *(string*)b)
		return 1;
	else if(*(string*)a < *(string*)b)
		return -1;
	else
		return 0;
}
void test_set(long& value)
{
	cout << "
test_set().......... 
";

	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)); //重复元素会被拒绝插入    					
		}
		catch(exception& p) 
		{
			cout << "i=" << i << " " << p.what() << endl;	
			abort();
		}
	}
	cout << "milli-seconds : " << (clock()-timeStart) << endl;		
	cout << "set.size()= " << c.size() << endl;//元素个数
	cout << "set.max_size()= " << c.max_size() << endl;	   //和计算机内存大小相关

	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;	
	}							
}		
int main()
{
	long int value;
	cout<<"how many elements: ";
	cin>>value;
	test_set(value);
	return 0;
}


 查看运行结果是否和我们预测的一样

 
 要求插入100万个元素，但是由于set本身不容许重复的特性，实际仅插入了998385个元素。
 
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