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:
- #include <iostream>
- #include <vector>//包含vector
- using namespace std;
-
- int main()
- {
- cout<<"----------vector test-----------"<<endl;
-
-
- vector <int> vect;
- vector <int> vect1(12);
- vector <int> vect2(12,9);
-
-
-
- int a[]={0,1,2,3,4,5,6,7,8,9,0};
-
- vector <int> vt(a+1,a+4);
-
- vt.push_back(1);
- vt.push_back(2);
- vt.push_back(3);
-
-
- vector <int>::iterator iter=vt.begin();
- vector <int>::iterator iter_end=vt.end();
-
- for(;iter!=iter_end;iter++)
- {
- cout<<*iter<<endl;
- }
-
-
- vt.pop_back();
-
-
- iter=vt.begin();
- iter_end=vt.end();
- cout<<"----------executed pop_back------"<<endl;
- for(;iter!=iter_end;iter++)
- {
- cout<<*iter<<endl;
- }
-
-
- cout<<"----------insert into------------"<<endl;
-
- vt.insert(vt.begin()+1,3,9);
- iter=vt.begin();
- iter_end=vt.end();
- for(;iter!=iter_end;iter++)
- {
- cout<<*iter<<endl;
- }
-
-
- cout<<"----------erase-------------------"<<endl;
-
-
- iter=vt.begin();
- iter_end=vt.end();
- vt.erase(iter+1,iter_end);
- 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:
- #include <iostream>
- #include <list>
- using namespace std;
-
- void main()
- {
- list<int> c1;
- c1.push_back(1);
- c1.push_back(2);
- c1.push_back(3);
- c1.push_back(4);
-
- c1.push_front(0);
-
- c1.pop_back();
- int& i = c1.back();
- const int& ii = c1.front();
-
-
- 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;
-
- list<int>::iterator it;
- 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:
-
-
-
-
-
-
-
-
-
-
- #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()
- {
-
- deque<int> d1;
- deque<int> d2(10);
- deque<double> d3(10, 5.5);
- deque<double> d4(d3);
-
-
- for (int i = 1; i < 6 ; i++)
- d1.push_back(i*10);
-
-
-
- cout<<"printDeque(d1) : "<<endl;
- printDeque(d1);
-
-
- cout<<"d1.push_front(100): "<<endl;
- d1.push_front(100);
- printDeque(d1);
- cout<<"d1.insert(d1.begin()+3, 200): "<<endl;
- d1.insert(d1.begin()+2,200);
- printDeque(d1);
-
-
-
- cout<<"d1.pop_front(): "<<endl;
- d1.pop_front();
- printDeque(d1);
-
- cout<<"d1.erase(d1.begin()+1): "<<endl;
- d1.erase(d1.begin()+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:
- <span style="font-size:16px;">#include <iostream>
- #include <Stack>
- using namespace std;
-
- void main()
- {
- stack<double> s;
- 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>
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:
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- #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:
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:
- #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 ;
-
-
- int i ;
-
- int value = 4 ;
-
-
- cout << "IntArray { " ;
- for(i = 0; i < ARRAY_SIZE; i++)
- cout << IntArray[i] << ", " ;
- cout << " }" << endl ;
-
-
-
- location = find(IntArray, IntArray + ARRAY_SIZE, value) ;
-
-
- if (location != IntArray + ARRAY_SIZE)
- cout << "First element that matches " << value
- << " is at location " << location - IntArray << endl;
- else
-
- 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 ;
-
- int i ;
-
-
- cout << "IntArray { " ;
- for(i = 0; i < ARRAY_SIZE; i++)
- cout << IntArray[i] << ", " ;
- cout << " }" << endl ;
-
-
-
- location = find_if(IntArray, IntArray + ARRAY_SIZE, IsOdd) ;
-
-
-
- if (location != IntArray + ARRAY_SIZE)
- cout << "First odd element " << *location
- << " is at location " << location - IntArray << endl;
- else
- 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:
- #include <iostream>
- #include <vector>
- #include <algorithm>
-
- using namespace std;
-
-
-
- void PrintCube(int n)
- {
- cout << n * n * n << " " ;
- }
-
- void main()
- {
- const int VECTOR_SIZE = 8 ;
-
-
- typedef vector<int > IntVector ;
-
-
- typedef IntVector::iterator IntVectorIt ;
-
- IntVector Numbers(VECTOR_SIZE) ;
-
- IntVectorIt start, end, it ;
-
- int i ;
-
-
- for (i = 0; i < VECTOR_SIZE; i++)
- Numbers[i] = i + 1 ;
-
- start = Numbers.begin() ;
-
-
- end = Numbers.end() ;
-
-
-
- cout << "Numbers { " ;
- for(it = start; it != end; it++)
- cout << *it << " " ;
- cout << " }\n" << endl ;
-
-
-
- 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:
- #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:
- #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;
- }
-
-
-
-
-
-
-
-
- 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());
- 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());
- 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:
- #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;
- }