C++容器

容器的分类

分为顺序容器（sequence） 关联容器（asscoiative） 无序容器（unordered）

顺序容器Array、vector、deque、list

关联容器有(mul)set和(mul)map，set和map的区别在于，set的key就是value，而map的key和value是分开的，set和map内部都是通过红黑树实现

无序容器主要为拉链法实现的散列表

测试辅助函数

using std::cin;using std::cout;using std::string;long get_a_target_long(){long target = 0;cout<<"target (0 ~"<<RAND_MAX<<"):";cin>>target;return target;}string get_a_target_string(){long target;char buf[10];cout<<"target (0 ~"<<RAND_MAX<<"):";cin>>target;snprintf(buf,10,"%d"target);return target;}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;elsereturn 0;}

 

1、Array

运行结果

 

 

const long ASIZE = 500000L;#include<array>#include<iostream>#include<ctime>#include<cstdlib>namespace JJ01{void test_array(){cout<<"test_array().......\n";//

std::array<long,ASIZE> c;clock_t timeStart = clock();for (long i = 0;i < ASIZE;i++){c[i] = rand();}//

cout << "milli-seconds : " << (clock() - timeStart)<<std::endl;//

cout << "array.size()= " << c.size() << std::endl;cout << "array.front()= " << c.front() << std::endl;cout << "array.back()= " << c.back() << std::endl;cout << "array.data()= " << c.data() << std::endl;//

long target = get_a_target_long();//

timeStart = clock();qsort(c.data(),ASIZE,sizeof(long),compareLongs);long* pItem = (long*)bsearch(&target,c.data(),ASIZE,sizeof(long),compareLongs);cout<<"qsort()+bsearch(),milli-sconds:"<<clock() - timeStart<<std::endl;if (pItem != NULL)cout<<"found,"<<*pItem<<std::endl;elsecout<<"not found!"<<std::endl;}}int main(){using namespace JJ01;test_array();return 0;}

 

2、Vector

关于vector的内存容量分配，如果vector发现内存容量不足时，会在当前容量的基础上变为原来的两倍(代码中的C++版本是这样的，后面版本变动可能会有所修改)，过程就是找一块可用内存，大小为当前内存的两倍，然后把数据拷贝过去，然后释放当前内存

 

 

const long ASIZE = 500000L;#include<vector>#include<stdexcept>#include<string>#include<cstdlib>#include<cstdio>#include<iostream>#include<ctime>#include<algorithm>namespace JJ02{void test_Vector(){cout<<"test_Vector()......."<<std::endl;//

std::vector<string> c;char buf[10];//

clock_t timeStart = clock();for (long i = 0;i <ASIZE;++i){try{_snprintf(buf,10,"%d",rand());c.push_back(string(buf));}catch(std::exception& p){cout<<"i = "<<i<<" "<<p.what()<<std::endl;//分配失败

abort();}}//

cout<<"milli-seconds : "<<(clock() - timeStart)<<std::endl;cout<<"vector.size() = "<<c.size()<<std::endl;cout<<"vector.front() = "<<c.front()<<std::endl;cout<<"vector.back() = "<<c.back()<<std::endl;cout<<"vector.data() = "<<c.data()<<std::endl;cout<<"vector.capacity() = "<<c.capacity()<<std::endl;//

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

{timeStart = clock();sort(c.begin(),c.end());string* pItem = (string*)bsearch(&target,c.data(),c.size(),sizeof(string),compareStrings);//

cout<<"sort() + bsearch(),milli-second = "<<(clock() - timeStart)<<std::endl;//

if (pItem != NULL)cout<<"find : "<<*pItem<<std::endl;elsecout<<"not found"<<std::endl;}}}int main(){using namespace JJ02;test_Vector();return 0;}

 

3、List和forward_list

 

list链表没有什么好讲的，比较常规，他分配内存的方式就是一个一个分配，

#include<list>#include<stdexcept>#include<string>#include<cstdlib>#include<cstdio>#include<iostream>#include<ctime>#include<algorithm>namespace JJ03{void test_List(){cout<<"test_List........"<<std::endl;//

std::list<string> c;char buf[10];clock_t timeStart = clock();//

for (long i = 0;i < ASIZE;i++){try{_snprintf(buf,10,"%d",rand());c.push_back(string(buf));}catch(std::exception& p) {cout<<"i = "<<i<<" "<<p.what()<<std::endl;abort();}}cout<<"milli-seconds : "<<(clock() - timeStart)<<std::endl;cout<<"list.size() : "<<c.size()<<std::endl;cout<<"list.max_size() : "<<c.max_size()<<std::endl;cout<<"list.front() : "<<c.front()<<std::endl;cout<<"list.back() : "<<c.back()<<std::endl;//

string target = get_a_target_string();timeStart = clock();auto pItem = std::find(c.begin(),c.end(),target);cout<<"std::find,milli-second : "<<(clock() - timeStart)<<std::endl;if (pItem != c.end())cout<<"find, Item = "<<*pItem<<std::endl;elsecout<<"not found!"<<std::endl;timeStart = clock();c.sort();cout<<"sort,milli-second : "<<(clock() - timeStart)<<std::endl;}}int main(){using namespace JJ03;test_List();return 0;}实现list的size和max_size/* Return the number of elements of in the list*/size_typesize() const _GILBCXX_NOEXCEPT{return std::distance(begin(),end());}/* return the size() of the largest posiible list*/size_typemax_size() _GILBCXX_NOEXCEPT{return _M_get_Node_allocator().max_size();}

 

运行截图

4、deque

通常我们认为deque中的中的元素是连续的，但其实不是，deque中存放的是一个个的buffer，每个buffer相当于一个数组，但是头尾都可以进行操作，当进行操作的时候，如果迭代器到了buffer的尾端需要进行判断，如果到了就需要切换到下一个buffer，每个buffer之间可能是不连续的，用指针相连，相当于是一个buffer的链表

#include<deque>#include<stdexcept>#include<string>#include<cstdlib>#include<cstdio>#include<iostream>#include<ctime>#include<algorithm>namespace JJ05{void test_deque(){cout<<"test_Deque()......."<<std::endl;//

std::deque<string> c;char buf[10];//

clock_t timeStart = clock();for (long i = 0;i <ASIZE;++i){try{_snprintf(buf,10,"%d",rand());c.push_back(string(buf));}catch(std::exception& p){cout<<"i = "<<i<<" "<<p.what()<<std::endl;//分配失败

abort();}}//

cout<<"milli-seconds : "<<(clock() - timeStart)<<std::endl;cout<<"deque.size() = "<<c.size()<<std::endl;cout<<"deque.front() = "<<c.front()<<std::endl;cout<<"deque.back() = "<<c.back()<<std::endl;//cout<<"deque.data() = "<<c.data()<<std::endl;

cout<<"deque.max_size() = "<<c.max_size()<<std::endl;//

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

{timeStart = clock();std::sort(c.begin(),c.end());//

cout<<"sort() + bsearch(),milli-second = "<<(clock() - timeStart)<<std::endl;}}}int main(){using namespace JJ05;test_deque();return 0;}

 

运行截图

 

5、stack和queue

 

stack和queue严格意义上不算container，而相当于adapter，因为他们相当于是deque的应用

所以说可以分为adapter而不是container

运行截图