这次把C++中的STL的一些东西练习一下下，STL全称为 Standard Template Library ，也就是标准模板库， 要使用STL，要了解以下几个基本概念：
容器：可以把它理解为存放数据的地方，常用的一些容器有 链表(list) 栈(stack) 动态数组 (vector) 双端队列(deque) 队列(queue) 映射(map)
游标(iterator)：可以把它理解为指针类型，STL中的许多函数需要用到它们作为参数
算法：它们通常需要与容器和游标配合使用，使用它们，你可以方便地对容器中的数据进行各种常见的操作，如排序操作，寻找最大元素的操作等
我只是简单的练习容器， 这个先是list双向链表代码，也只是简单的练习下，害怕自己忘记而已。
#include <iostream>
#include <list>
#include <cstdlib>
using namespace std;
int main(int argc, char** argv) {
int i;
list<char>lst;
for(i=0;i<10;i++)
lst.push_back('A'+(rand()%26));
cout<<"Original contents: ";
list<char>::iterator p = lst.begin();
while( p != lst.end()){
cout<<*p;
p++;
}
cout<<endl;
//sort the list
lst.sort();
cout<<"Sorted contents: ";
p = lst.begin();
while( p != lst.end()){
cout<<*p;
p++;
}
return 0;
}
map的使用
#include <iostream>
#include <map>
#include <string>
using namespace std;
int main(int argc, char** argv) {
int i;
map<string,string>m;
m.insert(pair<string,string>("yes","no"));
m.insert(pair<string,string>("up","down"));
m.insert(pair<string,string>("left","right"));
m.insert(pair<string,string>("cool","tong"));
string s;
cout<<"Enter word: ";
cin>>s;
map<string,string>::iterator p;
p = m.find(s);
if(p != m.end())
cout<<"Opposite:"<<p->second;
else
cout<<"Word not in map\n";
return 0;
}
queue的应用
#include <iostream>
#include <queue>
#include <string>
using namespace std;
int main(int argc, char** argv) {
queue<string>str_queue;
str_queue.push("string1");
str_queue.push("string2");
str_queue.push("string3");
cout<<"the size of the queue is:"<<str_queue.size()<<endl;
cout<<"the front one : "<<str_queue.front()<<endl;
cout<<"the back one : "<<str_queue.back()<<endl;
str_queue.pop();
str_queue.pop();
str_queue.pop();
if(str_queue.empty())
cout<<"the queue is empty"<<endl;
return 0;
}
vector的使用
#include <iostream>
#include <vector>
using namespace std;
int main(int argc, char** argv) {
vector<char>v;
int i;
for(i=0;i<10;i++)
v.push_back('A'+i);
for(i=0;i<10;i++)
cout<<v[i]<<" ";
cout<<endl;
vector<char>::iterator p = v.begin();
while( p!= v.end()){
cout<<*p<<" ";
p++;
}
return 0;
}
string的使用
#include <iostream>
#include<string>
using namespace std;
int main(int argc, char** argv) {
string a="abcedjnmbvnbm, cnm,bncm,bnm, nm,cnmm,klndslkfl sdnsdklnf ls";
cout<<a.length()<<endl;
cout<<a.size()<<endl;
cout<<a.capacity()<<endl;
cout<<a.max_size()<<endl;
return 0;
}
*************************************************************
#include <iostream>
#include<string>
using namespace std;
int main(int argc, char** argv) {
string a="abcdefghi";
string b="123456789";
string c="啦啦啦啦";
cout<<"比较字符串a和b"<<endl;
cout<<a.compare(b)<<endl;
a.swap(b);
cout<<"交换后a和b的输出"<<endl<<"输出a="<<a<<endl<<"输出b="<<b<<endl;
cout<<"查找"<<endl;
cout<<b.find('e',0)<<endl;
cout<<"熟悉replace"<<endl;
cout<<b.replace(0,5,a)<<endl;
cout<<"插入insert"<<endl;
cout<<b.insert(5,c)<<endl;
return 0;
}
*********************************************************************
#include <iostream>
#include<string>
using namespace std;
int main(int argc, char** argv) {
string str("this is an example sencetence.");
cout<<str<<endl;
str.erase(10,8);
cout<<str<<endl;
str.erase(str.begin()+9); //删除第9个
cout<<str<<endl;
str.erase(str.begin()+5,str.end()-9);
cout<<str<<endl;
return 0;
}
定义两个string类型的字符串，然后调用erase（），这个主要还是参数问题。只有一个参数就表示删除第几个位置的字符，begin（）和end（）只不过是开始和结束的位置，
******************************************************************************************
#include <iostream>
#include<string>
using namespace std;
int main(int argc, char** argv) {
string str("there are two needles in this haystack with needles.");
string str2("needle");
int found=str.find(str2);
if(found!=-1)
cout<<"first 'neeedle'found at:"<<found<<endl;
found=str.find("needle are small",found+1,6);//从pos开始查找字符串s中前n个字符在当前串中的位置
if(found!=-1)
cout<<"second 'needle' found at: "<<found<<endl ;
found=str.find("haystack");
cout << "'haystack' also found at: " << found <<endl;
found=str.find('.');
if(found!=-1)
cout << "Period found at: " << found << endl;
// 从str在字符串中找到str2的首位置并删除，然后加上后面的字符串
str.replace(str.find(str2),str2.length(),"preposition");
cout<<str<<endl;
return 0;
}
*****************************************************************************************************
#include <iostream>
#include<string>
using namespace std;
int main(int argc, char** argv) {
string base="this is a test string .";
string str2="n example";
string str3="sample phrase";
string str4="useful.";
string str=base;
cout<<str.replace(9,5,str2)<<endl;
cout<<str.replace(19,6,str3,7,6)<<endl;
cout<<str.replace(8,10,"just a")<<endl;
cout<<str.replace(8,6,"a shorty",7)<<endl;
cout<<str.replace(22,1,3,'!')<<endl;
cout<<str<<endl;
return 0;
}
运行结果
this is an example string .
this is an example phrase .
this is just a phrase .
this is a short phrase .
this is a short phrase!!!.
this is a short phrase!!!.
--------------------------------
Process exited with return value 0
Press any key to continue . . .
*********************************************************************************************************************************
#include <iostream>
#include<string>
using namespace std;
int main(int argc, char** argv) {
char ChangAn[20]={'\0'};
string str("Xi'an university of post & Telecommunication");
int length =str.copy(ChangAn,10,6);
cout<<"ChangAn contains: "<<ChangAn<<endl;
return 0;
}
copy是从字符串第6个位置开始然后复制10个字符到数组
*********************************************************************************************************************************
#include <iostream>
#include<string>
using namespace std;
int main(int argc, char** argv) {
string firstlevel("cn");
string secondlevel("edu");
string thirdlevel("xupt");
string scheme("http://");
string hostname;
string url;
hostname="www."+thirdlevel+'.'+secondlevel+'.'+firstlevel;
url=scheme+hostname;
cout<<url<<endl;
return 0;
}
在C++中+可以进行字符串的连接
*********************************************************************************************************************************
#include <iostream>
#include <string>
int main ()
{
string str1 ("green apple");
string str2 ("red apple");
if (str1.compare(str2) != 0)
cout << str1 << " is not " << str2 << '\n';
if (str1.compare(6,5,"apple") == 0)
cout << "still, " << str1 << " is an apple\n";
if (str2.compare(str2.size()-5,5,"apple") == 0)
cout << "and " << str2 << " is also an apple\n";
if (str1.compare(6,5,str2,4,5) == 0)
cout << "therefore, both are apples\n";
return 0;
时间： 2024-09-30 09:54:17