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常用STL容器及算法举例

2013-10-08 11:09 411 查看

一 常用容器举例

1 vector:

vector类似于动态数组,直接访问元素,从后面快速插入或者删除,示例代码如下:

[cpp]
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#include <iostream>
#include <vector>//包含vector
using namespace std;//指定命名空间

int main()
{
cout<<"----------vector test-----------"<<endl;

//定义一个vector
vector <int> vect;
vector <int> vect1(12);//12个int类型元素,每个元素的初始值均为0

vector <int> vect2(12,9);//12个int,初试值均为9

//使用数组初始化vector
int a[]={0,1,2,3,4,5,6,7,8,9,0};
//vector <数据类型> <容器名> (<开始地址>,<结束地址的下一个地址> )。执行过vt中元素为1,2,3

vector <int> vt(a+1,a+4);
//在尾部压入3个值
vt.push_back(1);
vt.push_back(2);
vt.push_back(3);

//定义迭代器iterator
vector <int>::iterator iter=vt.begin();//起始地址

vector <int>::iterator iter_end=vt.end();//结束地址,两个地址都是指针类型

//遍历vt
for(;iter!=iter_end;iter++)
{
cout<<*iter<<endl;
}

//弹出一个元素
vt.pop_back();

//以下两行重新获得起始和结尾地址
iter=vt.begin();
iter_end=vt.end();
cout<<"----------executed pop_back------"<<endl;
for(;iter!=iter_end;iter++)
{
cout<<*iter<<endl;
}

//插入元素
cout<<"----------insert into------------"<<endl;
//插入格式:vector.insert(<起始地址>,<插入的数量>,<元素值>);如果插入的数量为1,则第二个参数可以被省略

vt.insert(vt.begin()+1,3,9);
iter=vt.begin();
iter_end=vt.end();
for(;iter!=iter_end;iter++)
{
cout<<*iter<<endl;
}

//删除元素
cout<<"----------erase-------------------"<<endl;
//删除格式1为:vector.erase(<删除元素的地址>);

//删除格式2为:vector.erase(<删除元素的起始地址>,<终止地址>);

iter=vt.begin();
iter_end=vt.end();
vt.erase(iter+1,iter_end);//删除第二个到最后一个的元素

iter_end=vt.end();
for(;iter!=iter_end;iter++)
{
cout<<*iter<<endl;
}
return 1;
}

#include <iostream>
#include <vector>//包含vector
using namespace std;//指定命名空间

int main()
{
cout<<"----------vector test-----------"<<endl;

//定义一个vector
vector <int> vect;
vector <int> vect1(12);//12个int类型元素,每个元素的初始值均为0
vector <int> vect2(12,9);//12个int,初试值均为9

//使用数组初始化vector
int a[]={0,1,2,3,4,5,6,7,8,9,0};
//vector <数据类型> <容器名> (<开始地址>,<结束地址的下一个地址> )。执行过vt中元素为1,2,3
vector <int> vt(a+1,a+4);
//在尾部压入3个值
vt.push_back(1);
vt.push_back(2);
vt.push_back(3);

//定义迭代器iterator
vector <int>::iterator iter=vt.begin();//起始地址
vector <int>::iterator iter_end=vt.end();//结束地址,两个地址都是指针类型
//遍历vt
for(;iter!=iter_end;iter++)
{
cout<<*iter<<endl;
}

//弹出一个元素
vt.pop_back();

//以下两行重新获得起始和结尾地址
iter=vt.begin();
iter_end=vt.end();
cout<<"----------executed pop_back------"<<endl;
for(;iter!=iter_end;iter++)
{
cout<<*iter<<endl;
}

//插入元素
cout<<"----------insert into------------"<<endl;
//插入格式:vector.insert(<起始地址>,<插入的数量>,<元素值>);如果插入的数量为1,则第二个参数可以被省略
vt.insert(vt.begin()+1,3,9);
iter=vt.begin();
iter_end=vt.end();
for(;iter!=iter_end;iter++)
{
cout<<*iter<<endl;
}

//删除元素
cout<<"----------erase-------------------"<<endl;
//删除格式1为:vector.erase(<删除元素的地址>);
//删除格式2为:vector.erase(<删除元素的起始地址>,<终止地址>);
iter=vt.begin();
iter_end=vt.end();
vt.erase(iter+1,iter_end);//删除第二个到最后一个的元素
iter_end=vt.end();
for(;iter!=iter_end;iter++)
{
cout<<*iter<<endl;
}
return 1;
}


2 list

list 为双向链表,可以从任何地方插入或者删除的,其示例代码如下:

[cpp]
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#include <iostream>
#include <list>
using namespace std;

void main()
{
list<int> c1;
c1.push_back(1);//从尾部push数据(结点)到list中

c1.push_back(2);
c1.push_back(3);
c1.push_back(4);

c1.push_front(0);//从头部push数据(结点)到list中

c1.pop_back();//从尾部pop数据(结点)出去

int& i = c1.back();//获取list中尾部数据(结点)

const int& ii = c1.front();//获取list中头部 数据(结点)

cout << "The last integer of c1 is " << i << endl;
cout << "The front interger of c1 is " << ii << endl;

cout << "for循环读出数据举例:" << endl;
//循环遍历数据举例
list<int>::iterator it; //定义遍历指示器(类似于int i=0)

for(it = c1.begin() ; it != c1.end() ;it++)
{
cout << *it << endl;
}
system("pause");
}

#include <iostream>
#include <list>
using namespace std;

void main()
{
list<int> c1;
c1.push_back(1);//从尾部push数据(结点)到list中
c1.push_back(2);
c1.push_back(3);
c1.push_back(4);

c1.push_front(0);//从头部push数据(结点)到list中

c1.pop_back();//从尾部pop数据(结点)出去
int& i = c1.back();//获取list中尾部数据(结点)
const int& ii = c1.front();//获取list中头部 数据(结点)

cout << "The last integer of c1 is " << i << endl;
cout << "The front interger of c1 is " << ii << endl;

cout << "for循环读出数据举例:" << endl;
//循环遍历数据举例
list<int>::iterator it; //定义遍历指示器(类似于int i=0)
for(it = c1.begin() ; it != c1.end() ;it++)
{
cout << *it << endl;
}
system("pause");
}




3 deque:

deque: 是一个double-ended queue,

1)支持随即存取,也就是[]操作符,

2)支持两端操作,push(pop)-back(front),在两端操作上与list效率差不多

因此在实际使用时,如何选择这三个容器中哪一个,应根据你的需要而定,一般应遵循下面的原则:

1、如果你需要高效的随即存取,而不在乎插入和删除的效率,使用vector

2、如果你需要大量的插入和删除,而不关心随即存取,则应使用list

3、如果你需要随即存取,而且关心两端数据的插入和删除,则应使用deque。

示例代码如下:

[cpp]
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/*deque: 是一个double-ended queue,
1)支持随即存取,也就是[]操作符,
2)支持两端操作,push(pop)-back(front),在两端操作上与list效率差不多

因此在实际使用时,如何选择这三个容器中哪一个,应根据你的需要而定,一般应遵循下面的原则:
1、如果你需要高效的随即存取,而不在乎插入和删除的效率,使用vector
2、如果你需要大量的插入和删除,而不关心随即存取,则应使用list
3、如果你需要随即存取,而且关心两端数据的插入和删除,则应使用deque。
*/

#include <iostream>

#include <deque>
using namespace std;

void printDeque(const deque<int>& d)
{
cout<<"\n使用下标:\n";
for (unsigned int i = 0; i < d.size(); i++)
{
cout<<"d["<<i<<"] = "<<d[i]<<", ";
}

cout<<"\n使用迭代器\n";
deque<int>::const_iterator iter = d.begin();
for (;iter != d.end(); iter ++)
{
cout<<"d["<<iter-d.begin()<<"] = "<<(*iter)<<", ";
}
cout<<endl;
}

void main()
{
//创建deque
deque<int> d1; //创建一个没有任何元素的deque对象

deque<int> d2(10); //创建一个具有10个元素的deque对象,每个元素值为默认

deque<double> d3(10, 5.5); //创建一个具有10个元素的deque对象,每个元素的初始值为5.5

deque<double> d4(d3); //通过拷贝一个deque对象的元素值, 创建一个新的deque对象

//初始化赋值:同vector一样,使用尾部插入函数push_back()

for (int i = 1; i < 6 ; i++)
d1.push_back(i*10);

//遍历元素: 1-下标方式 2-迭代器方式 反向遍历(略)
cout<<"printDeque(d1) : "<<endl;
printDeque(d1);

//元素插入:尾部插入用push_back(),头部插入用push_front(),其它位置插入用insert(&pos, elem)

cout<<"d1.push_front(100): "<<endl;
d1.push_front(100);
printDeque(d1);
cout<<"d1.insert(d1.begin()+3, 200): "<<endl; //支持随机存取(即[]操作符),所以begin()可以+3

d1.insert(d1.begin()+2,200);
printDeque(d1);

//元素删除 尾部删除用pop_back();头部删除用pop_front();

//任意迭代位置或迭代区间上的元素删除用erase(&pos)/erase(&first, &last);删除所有元素用clear();

cout<<"d1.pop_front(): "<<endl;
d1.pop_front();
printDeque(d1);

cout<<"d1.erase(d1.begin()+1): "<<endl;
d1.erase(d1.begin()+1); //删除第2个元素d1[1]

printDeque(d1);

cout<<"d1.erase(d1.begin(), d1.begin() + 2) = "<<endl;
d1.erase(d1.begin(), d1.begin() + 2);
printDeque(d1);

cout<<"d1.clear() :"<<endl;
d1.clear();
printDeque(d1);

}

/*deque: 是一个double-ended queue,
1)支持随即存取,也就是[]操作符,
2)支持两端操作,push(pop)-back(front),在两端操作上与list效率差不多

因此在实际使用时,如何选择这三个容器中哪一个,应根据你的需要而定,一般应遵循下面的原则:
1、如果你需要高效的随即存取,而不在乎插入和删除的效率,使用vector
2、如果你需要大量的插入和删除,而不关心随即存取,则应使用list
3、如果你需要随即存取,而且关心两端数据的插入和删除,则应使用deque。
*/

#include <iostream>
#include <deque>
using namespace std;

void printDeque(const deque<int>& d)
{
cout<<"\n使用下标:\n";
for (unsigned int i = 0; i < d.size(); i++)
{
cout<<"d["<<i<<"] = "<<d[i]<<", ";
}

cout<<"\n使用迭代器\n";
deque<int>::const_iterator iter = d.begin();
for (;iter != d.end(); iter ++)
{
cout<<"d["<<iter-d.begin()<<"] = "<<(*iter)<<", ";
}
cout<<endl;
}

void main()
{
//创建deque
deque<int> d1;                          //创建一个没有任何元素的deque对象
deque<int> d2(10);                      //创建一个具有10个元素的deque对象,每个元素值为默认
deque<double> d3(10, 5.5);              //创建一个具有10个元素的deque对象,每个元素的初始值为5.5
deque<double> d4(d3);                   //通过拷贝一个deque对象的元素值, 创建一个新的deque对象

//初始化赋值:同vector一样,使用尾部插入函数push_back()
for (int i = 1; i < 6 ; i++)
d1.push_back(i*10);

//遍历元素: 1-下标方式 2-迭代器方式 反向遍历(略)
cout<<"printDeque(d1) : "<<endl;
printDeque(d1);

//元素插入:尾部插入用push_back(),头部插入用push_front(),其它位置插入用insert(&pos, elem)
cout<<"d1.push_front(100): "<<endl;
d1.push_front(100);
printDeque(d1);
cout<<"d1.insert(d1.begin()+3, 200): "<<endl; //支持随机存取(即[]操作符),所以begin()可以+3
d1.insert(d1.begin()+2,200);
printDeque(d1);

//元素删除 尾部删除用pop_back();头部删除用pop_front();
//任意迭代位置或迭代区间上的元素删除用erase(&pos)/erase(&first, &last);删除所有元素用clear();
cout<<"d1.pop_front(): "<<endl;
d1.pop_front();
printDeque(d1);

cout<<"d1.erase(d1.begin()+1): "<<endl;
d1.erase(d1.begin()+1); //删除第2个元素d1[1]
printDeque(d1);

cout<<"d1.erase(d1.begin(), d1.begin() + 2) = "<<endl;
d1.erase(d1.begin(), d1.begin() + 2);
printDeque(d1);

cout<<"d1.clear() :"<<endl;
d1.clear();
printDeque(d1);

}




4 容器适配器:stack

(1)可用 vector, list, deque来实现

(2)缺省情况下,用deque实现

template<classT, class Cont = deque<T> >

class stack { ….. };

(3)用 vector和deque实现,比用list实现性能好

(4)stack是后进先出的数据结构,

(5)只能插入、删除、访问栈顶的元素的操作:
push:
插入元素pop:
弹出元素 top:
返回栈顶元素的引用

测试代码如下:

[cpp]
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<SPAN style="FONT-SIZE: 16px">#include <iostream>
#include <Stack>
using namespace std;

void main()
{
stack<double> s;//可以是各种数据类型;

for( int i=0; i < 10; i++ )
s.push(i);
while(!s.empty())
{
printf("%lf\n",s.top());
s.pop();
}
cout << "the size of s: " << s.size() << endl;
}
</SPAN>

#include <iostream>
#include <Stack>
using namespace std;

void main()
{
stack<double> s;//可以是各种数据类型;
for( int i=0; i < 10; i++ )
s.push(i);
while(!s.empty())
{
printf("%lf\n",s.top());
s.pop();
}
cout << "the size of  s: " << s.size() << endl;
}


5 deque

可以用 list和deque实现,缺省情况下用deque实现

template<class T, class Cont = deque<T>>

class queue { … };

FIFO先进先出的数据结构,也有push,pop,top函数,但是push发生在队尾,pop,top发生在队头,

示例代码如下:

[cpp]
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/************************************************************************/
/*

详细用法:
定义一个queue的变量 queue<Type> M
查看是否为空范例 M.empty() 是的话返回1,不是返回0;
从已有元素后面增加元素 M.push()
输出现有元素的个数 M.size()
显示第一个元素 M.front()
显示最后一个元素 M.back()
清除第一个元素 M.pop()
*/
/************************************************************************/

#include <iostream>

#include <queue>
#include <assert.h>

using namespace std;

int main()
{
queue <int> myQ;
int i;
cout<< "现在 queue 是否 empty? "<< myQ.empty() << endl;

for( i =0; i<10 ; i++)
{
myQ.push(i);
}
for( i=0; i<myQ.size(); i++)
{
printf("myQ.size():%d\n",myQ.size());
cout << myQ.front()<<endl;
myQ.pop();
}

system("PAUSE");

return 0;
}

/************************************************************************/
/*

详细用法:
定义一个queue的变量     queue<Type> M
查看是否为空范例        M.empty()    是的话返回1,不是返回0;
从已有元素后面增加元素   M.push()
输出现有元素的个数      M.size()
显示第一个元素          M.front()
显示最后一个元素        M.back()
清除第一个元素          M.pop()
*/
/************************************************************************/

#include <iostream>
#include <queue>
#include <assert.h>

using namespace std;

int main()
{
queue <int> myQ;
int i;
cout<< "现在 queue 是否 empty? "<< myQ.empty() << endl;

for( i =0; i<10 ; i++)
{
myQ.push(i);
}
for( i=0; i<myQ.size(); i++)
{
printf("myQ.size():%d\n",myQ.size());
cout << myQ.front()<<endl;
myQ.pop();
}

system("PAUSE");

return 0;
}


二 常用算法

1 count()and count_if()

count()在序列中统计某个值出现的次数
count_if()在序列中统计与某谓词匹配的次数
示例代码如下:

[cpp]
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#include <iostream>
#include <algorithm>
#include <functional>

#include <string>
#include <vector>

using namespace std;

void CountFuc()
{
const int VECTOR_SIZE = 8 ;

// Define a template class vector of strings

typedef vector<string > StringVector ;

//Define an iterator for template class vector of strings

typedef StringVector::iterator StringVectorIt ;

StringVector NamesVect(VECTOR_SIZE) ; //vector containing names

string value("Sea") ; // stores the value used

// to count matching elements

StringVectorIt start, end, it ;

int result = 0 ; // stores count of elements

// that match value.

// Initialize vector NamesVect

NamesVect[0] = "She" ;
NamesVect[1] = "Sells" ;
NamesVect[2] = "Sea" ;
NamesVect[3] = "Shells" ;
NamesVect[4] = "by" ;
NamesVect[5] = "the" ;
NamesVect[6] = "Sea" ;
NamesVect[7] = "Shore" ;

start = NamesVect.begin() ; // location of first

// element of NamesVect

end = NamesVect.end() ; // one past the location

// last element of NamesVect

// print content of NamesVect
cout << "NamesVect { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;

// Count the number of elements in the range [first, last +1)

// that match value.

result = count(start, end, value) ;

// print the count of elements that match value

cout << "Number of elements that match \"Sea\" = "
<< result << endl ;
}

int MatchFirstChar( const string& str)
{
string s("S") ;
return s == str.substr(0,1) ;
}

void CountIfFuc()
{
const int VECTOR_SIZE = 8 ;

// Define a template class vector of strings

typedef vector<string > StringVector ;

//Define an iterator for template class vector of strings

typedef StringVector::iterator StringVectorIt ;

StringVector NamesVect(VECTOR_SIZE) ; //vector containing names

StringVectorIt start, end, it ;

int result = 0 ; // stores count of elements

// that match value.

// Initialize vector NamesVect

NamesVect[0] = "She" ;
NamesVect[1] = "Sells" ;
NamesVect[2] = "Sea" ;
NamesVect[3] = "Shells" ;
NamesVect[4] = "by" ;
NamesVect[5] = "the" ;
NamesVect[6] = "Sea" ;
NamesVect[7] = "Shore" ;

start = NamesVect.begin() ; // location of first

// element of NamesVect

end = NamesVect.end() ; // one past the location

// last element of NamesVect

// print content of NamesVect
cout << "NamesVect { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;

// Count the number of elements in the range [first, last +1)

// that start with letter 'S'

result = count_if(start, end, MatchFirstChar) ;

// print the count of elements that start with letter 'S'

cout << "Number of elements that start with letter \"S\" = "
<< result << endl ;
}

void main()
{
CountFuc();
CountIfFuc();
}

#include <iostream>
#include <algorithm>
#include <functional>
#include <string>
#include <vector>

using namespace std;

void CountFuc()
{
const int VECTOR_SIZE = 8 ;

// Define a template class vector of strings
typedef vector<string > StringVector ;

//Define an iterator for template class vector of strings
typedef StringVector::iterator StringVectorIt ;

StringVector NamesVect(VECTOR_SIZE) ;   //vector containing names

string value("Sea") ;  // stores the value used
// to count matching elements

StringVectorIt start, end, it ;

int result = 0 ;   // stores count of elements
// that match value.

// Initialize vector NamesVect
NamesVect[0] = "She" ;
NamesVect[1] = "Sells" ;
NamesVect[2] = "Sea" ;
NamesVect[3] = "Shells" ;
NamesVect[4] = "by" ;
NamesVect[5] = "the" ;
NamesVect[6] = "Sea" ;
NamesVect[7] = "Shore" ;

start = NamesVect.begin() ;   // location of first
// element of NamesVect

end = NamesVect.end() ;       // one past the location
// last element of NamesVect

// print content of NamesVect
cout << "NamesVect { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;

// Count the number of elements in the range [first, last +1)
// that match value.
result = count(start, end, value) ;

// print the count of elements that match value
cout << "Number of elements that match \"Sea\" = "
<< result << endl  ;
}

int MatchFirstChar( const string& str)
{
string s("S") ;
return s == str.substr(0,1) ;
}

void CountIfFuc()
{
const int VECTOR_SIZE = 8 ;

// Define a template class vector of strings
typedef vector<string > StringVector ;

//Define an iterator for template class vector of strings
typedef StringVector::iterator StringVectorIt ;

StringVector NamesVect(VECTOR_SIZE) ;   //vector containing names

StringVectorIt start, end, it ;

int result = 0 ;   // stores count of elements
// that match value.

// Initialize vector NamesVect
NamesVect[0] = "She" ;
NamesVect[1] = "Sells" ;
NamesVect[2] = "Sea" ;
NamesVect[3] = "Shells" ;
NamesVect[4] = "by" ;
NamesVect[5] = "the" ;
NamesVect[6] = "Sea" ;
NamesVect[7] = "Shore" ;

start = NamesVect.begin() ;   // location of first
// element of NamesVect

end = NamesVect.end() ;       // one past the location
// last element of NamesVect

// print content of NamesVect
cout << "NamesVect { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;

// Count the number of elements in the range [first, last +1)
// that start with letter 'S'
result = count_if(start, end, MatchFirstChar) ;

// print the count of elements that start with letter 'S'
cout << "Number of elements that start with letter \"S\" = "
<< result << endl  ;
}

void main()
{
CountFuc();
CountIfFuc();
}




2 find and find_if

find 在序列中找出某个值的第一次出现的位置

find_if 在序列中找出符合某谓词的第一个元素
示例代码如下:

[cpp]
view plaincopyprint?

#include <algorithm>
#include <iostream>

using namespace std;

void FindFuc()
{
const int ARRAY_SIZE = 8 ;
int IntArray[ARRAY_SIZE] = { 1, 2, 3, 4, 4, 5, 6, 7 } ;

int *location ; // stores the position of the first

// matching element.

int i ;

int value = 4 ;

// print content of IntArray

cout << "IntArray { " ;
for(i = 0; i < ARRAY_SIZE; i++)
cout << IntArray[i] << ", " ;
cout << " }" << endl ;

// Find the first element in the range [first, last + 1)

// that matches value.
location = find(IntArray, IntArray + ARRAY_SIZE, value) ;

//print the matching element if any was found

if (location != IntArray + ARRAY_SIZE) // matching element found

cout << "First element that matches " << value
<< " is at location " << location - IntArray << endl;
else // no matching element was

// found
cout << "The sequence does not contain any elements"
<< " with value " << value << endl ;
}

int IsOdd( int n)
{
return n % 2 ;
}

void FindIfFuc()
{
const int ARRAY_SIZE = 8 ;
int IntArray[ARRAY_SIZE] = { 1, 2, 3, 4, 4, 5, 6, 7 } ;
int *location ; // stores the position of the first

// element that is an odd number

int i ;

// print content of IntArray

cout << "IntArray { " ;
for(i = 0; i < ARRAY_SIZE; i++)
cout << IntArray[i] << ", " ;
cout << " }" << endl ;

// Find the first element in the range [first, last -1 ]

// that is an odd number
location = find_if(IntArray, IntArray + ARRAY_SIZE, IsOdd) ;

//print the location of the first element

// that is an odd number
if (location != IntArray + ARRAY_SIZE) // first odd element found

cout << "First odd element " << *location
<< " is at location " << location - IntArray << endl;
else // no odd numbers in the range

cout << "The sequence does not contain any odd numbers"
<< endl ;

}

void main()
{
FindFuc();
FindIfFuc();
}

#include <algorithm>
#include <iostream>

using namespace std;

void FindFuc()
{
const int ARRAY_SIZE = 8 ;
int IntArray[ARRAY_SIZE] = { 1, 2, 3, 4, 4, 5, 6, 7 } ;

int *location ;   // stores the position of the first
// matching element.

int i ;

int value = 4 ;

// print content of IntArray
cout << "IntArray { " ;
for(i = 0; i < ARRAY_SIZE; i++)
cout << IntArray[i] << ", " ;
cout << " }" << endl ;

// Find the first element in the range [first, last + 1)
// that matches value.
location = find(IntArray, IntArray + ARRAY_SIZE, value) ;

//print the matching element if any was found
if (location != IntArray + ARRAY_SIZE)  // matching element found
cout << "First element that matches " << value
<< " is at location " << location - IntArray << endl;
else                                    // no matching element was
// found
cout << "The sequence does not contain any elements"
<< " with value " << value << endl ;
}

int IsOdd( int n)
{
return n % 2 ;
}

void FindIfFuc()
{
const int ARRAY_SIZE = 8 ;
int IntArray[ARRAY_SIZE] = { 1, 2, 3, 4, 4, 5, 6, 7 } ;
int *location ;   // stores the position of the first
// element that is an odd number
int i ;

// print content of IntArray
cout << "IntArray { " ;
for(i = 0; i < ARRAY_SIZE; i++)
cout << IntArray[i] << ", " ;
cout << " }" << endl ;

// Find the first element in the range [first, last -1 ]
// that is an odd number
location = find_if(IntArray, IntArray + ARRAY_SIZE, IsOdd) ;

//print the location of the first element
// that is an odd number
if (location != IntArray + ARRAY_SIZE)  // first odd element found
cout << "First odd element " << *location
<< " is at location " << location - IntArray << endl;
else         // no odd numbers in the range
cout << "The sequence does not contain any odd numbers"
<< endl ;

}

void main()
{
FindFuc();
FindIfFuc();
}


3 for_each()

函数声明如下:
template<class InIt, class Fun>
Fun for_each(InIt first, InIt last, Fun f);

在区间【first,last)上的每个元素执行f操作
示例代码如下:

[cpp]
view plaincopyprint?

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

// prints the cube of integer n
void PrintCube(int n)
{
cout << n * n * n << " " ;
}

void main()
{
const int VECTOR_SIZE = 8 ;

// Define a template class vector of integers

typedef vector<int > IntVector ;

//Define an iterator for template class vector of integer

typedef IntVector::iterator IntVectorIt ;

IntVector Numbers(VECTOR_SIZE) ; //vector containing numbers

IntVectorIt start, end, it ;

int i ;

// Initialize vector Numbers
for (i = 0; i < VECTOR_SIZE; i++)
Numbers[i] = i + 1 ;

start = Numbers.begin() ; // location of first

// element of Numbers

end = Numbers.end() ; // one past the location

// last element of Numbers

// print content of Numbers
cout << "Numbers { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;

// for each element in the range [first, last)

// print the cube of the element

for_each(start, end, PrintCube) ;
cout << "\n\n" ;
}

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

// prints the cube of integer n
void PrintCube(int n)
{
cout << n * n * n << " " ;
}

void main()
{
const int VECTOR_SIZE = 8 ;

// Define a template class vector of integers
typedef vector<int > IntVector ;

//Define an iterator for template class vector of integer
typedef IntVector::iterator IntVectorIt ;

IntVector Numbers(VECTOR_SIZE) ;   //vector containing numbers

IntVectorIt start, end, it ;

int i ;

// Initialize vector Numbers
for (i = 0; i < VECTOR_SIZE; i++)
Numbers[i] = i + 1 ;

start = Numbers.begin() ;   // location of first
// element of Numbers

end = Numbers.end() ;       // one past the location
// last element of Numbers

// print content of Numbers
cout << "Numbers { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;

// for each element in the range [first, last)
// print the cube of the element
for_each(start, end, PrintCube) ;
cout << "\n\n" ;
}


4 unique

unique --常用来删除重复的元素,将相邻的重复的元素移到最后,返回一个iterator指向最后的重复元素,所以用它来删除重复元素时必须先排序
示例代码如下:

[cpp]
view plaincopyprint?

#include <iostream>
#include <algorithm>
#include <vector>

#include <string>
using namespace std;

void main()
{
string str;
vector<string> words;
while(cin>>str&&str!="#")
{
words.push_back(str);
}

sort(words.begin(),words.end());
vector<string>::iterator end_unique =
unique(words.begin(),words.end());
words.erase(end_unique,words.end());

vector<string> ::iterator ite=words.begin();
for(;ite!=words.end();ite++)
{
cout<<*ite<<" ";
}

cout<<endl;
}

#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;

void main()
{
string str;
vector<string> words;
while(cin>>str&&str!="#")
{
words.push_back(str);
}

sort(words.begin(),words.end());
vector<string>::iterator end_unique =
unique(words.begin(),words.end());
words.erase(end_unique,words.end());

vector<string> ::iterator ite=words.begin();
for(;ite!=words.end();ite++)
{
cout<<*ite<<"	";
}

cout<<endl;
}


5 常用排序算法

常用排列算法如下:

1 sort 对给定区间所有元素进行排序

2 stable_sort 对给定区间所有元素进行稳定排序

3 partial_sort 对给定区间所有元素部分排序

4 partial_sort_copy 对给定区间复制并排序
示例代码如下:

[cpp]
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#include <iostream>
#include <algorithm>
#include <stdlib.h>

#include <time.h>
#include <VECTOR>

using namespace std;

const int N=10;

void print(const vector<int>& v)
{
vector<int>::const_iterator ite=v.begin();
for(;ite!=v.end();ite++)
{
cout<<*ite<<" ";
}

cout<<endl;
}

void Create(vector<int>& v)
{
srand((unsigned int)time(NULL));
v.resize(N);
for(int i=0;i<N;i++)
v[i]=rand()%100;
}

// bool cmp(int arg1,int arg2)

// {
// return arg1<arg2;
// }

void sort1(vector<int> v)
{
sort(v.begin(),v.end());
cout<<"after sort funtion:\n";
print(v);
}

void sort2(vector<int> v)
{
stable_sort(v.begin(),v.end());
cout<<"after stable_sort funtion:\n";
print(v);
}

void sort3(vector<int> v)
{
partial_sort(v.begin(),v.begin()+v.size()/2,v.end()); //对前半部分排序

cout<<"after partial_sort funtion:\n";
print(v);
}

void sort4(vector<int> v)
{
vector<int> temp;
temp.resize(v.size());
partial_sort_copy(v.begin(),v.end(),temp.begin(),temp.end()); //复制并排序

cout<<"after partial_sort_copy funtion:\n";
print(temp);
}

void main()
{
vector<int> v;

Create(v);
cout<<"before sort:\n";
print(v);

sort1(v);
sort2(v);
sort3(v);
sort4(v);
}

#include <iostream>
#include <algorithm>
#include <stdlib.h>
#include <time.h>
#include <VECTOR>
using namespace std;

const int N=10;

void print(const vector<int>& v)
{
vector<int>::const_iterator ite=v.begin();
for(;ite!=v.end();ite++)
{
cout<<*ite<<"  ";
}

cout<<endl;
}

void Create(vector<int>& v)
{
srand((unsigned int)time(NULL));
v.resize(N);
for(int i=0;i<N;i++)
v[i]=rand()%100;
}

// bool cmp(int arg1,int arg2)
// {
// 	return arg1<arg2;
// }

void sort1(vector<int> v)
{
sort(v.begin(),v.end());
cout<<"after sort funtion:\n";
print(v);
}

void sort2(vector<int> v)
{
stable_sort(v.begin(),v.end());
cout<<"after stable_sort funtion:\n";
print(v);
}

void sort3(vector<int> v)
{
partial_sort(v.begin(),v.begin()+v.size()/2,v.end()); //对前半部分排序
cout<<"after partial_sort funtion:\n";
print(v);
}

void sort4(vector<int> v)
{
vector<int> temp;
temp.resize(v.size());
partial_sort_copy(v.begin(),v.end(),temp.begin(),temp.end()); //复制并排序
cout<<"after partial_sort_copy funtion:\n";
print(temp);
}

void main()
{
vector<int> v;

Create(v);
cout<<"before sort:\n";
print(v);

sort1(v);
sort2(v);
sort3(v);
sort4(v);
}




6 生成全排列

next_permutation()的原型如下:
template<class BidirectionalIterator>

bool next_permutation(

BidirectionalIterator _First,

BidirectionalIterator _Last

);

template<class BidirectionalIterator, class BinaryPredicate>

bool next_permutation(

BidirectionalIterator _First,

BidirectionalIterator _Last,

BinaryPredicate _Comp

);

两个重载函数,第二个带谓词参数_Comp,其中只带两个参数的版本,默认谓词函数为"小于".,返回值为bool类型
示例代码如下:

[cpp]
view plaincopyprint?

#include <iostream>
#include <algorithm>
using namespace std;

void permutation(char* str,int length)
{
sort(str,str+length);
do
{
for(int i=0;i<length;i++)
cout<<str[i];
cout<<endl;
}while(next_permutation(str,str+length));

}
int main(void)
{
char str[] = "acb";
cout<<str<<"所有全排列的结果为:"<<endl;
permutation(str,3);
system("pause");
return 0;
}
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