stl vector 筆記

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Vector 為類模板

使用例子：

#include <iostream>#include <vector>#include <string>using namespace std;int main(int argc , char *argv[]){   vector<string> SS;   SS.push_back("The number is 10");   SS.push_back("The number is 20");   SS.push_back("The number is 30");   cout << "Loop by index:" << endl;   int ii;   for(ii=0; ii < SS.size(); ii++)   {      cout << SS[ii] << endl;   }   cout << endl << "Constant Iterator:" << endl;   vector<string>::const_iterator cii;   for(cii=SS.begin(); cii!=SS.end(); cii++)   {      cout << *cii << endl;   }   cout << endl << "Reverse Iterator:" << endl;   vector<string>::reverse_iterator rii;   for(rii=SS.rbegin(); rii!=SS.rend(); ++rii)   {      cout << *rii << endl;   }   cout << endl << "Sample Output:" << endl;   cout << SS.size() << endl;   cout << SS[2] << endl;   swap(SS[0], SS[2]);   cout << SS[2] << endl;   return 0;}

編譯： g++ example.cpp 

需要注意的是 end() 指向最後一個資料的下一個指標，所以不能指向最後一個元素，如：

iter_jj = SS.end();cout << *iter_jj << endl;

這會導致  "Segmentation fault" error. 端錯誤。

stl vector 實現了動態數組功能，可以儲存 基本資料，對象，與list同屬於線性容器，優點是擷取對象快，缺點是尋找慢，

stl vector 模板提供了大量的操作vetror 方法， 包括 初始化，插入，刪除，容量相關的方法， 另一塊為遍曆vector介面iterator.

下面附上 vector模板提供的介面：

 

建構函式：

Method/operator	Description
vector<T> v;	Vector declaration of data type "T".
vector<T> v(size_type n);	Declaration of vector containing type "T" and of size "n" (quantity).
vector<T> v(size_type n,const T& t);	Declaration of vector containing type "T", of size "n" (quantity) containing value "t". Declaration: vector(size_type n, const T& t)
vector<T> v(begin_iterator,end_iterator);	Copy of Vector of data type "T" and range begin_iterator to end_iterator. Declaration: template vector(InputIterator, InputIterator)

與 Size 相關的 methods/operators:

Method/operator	Description
empty()	Returns bool (true/false). True if empty. Declaration: bool empty() const
size()	Number of elements of vector. Declaration: size_type size() const
resize(n, t=T())	Adjust by adding or deleting elements of vector so that its size is "n". Declaration: void resize(n, t = T())
capacity()	Max number of elements of vector before reallocation. Declaration: size_type capacity() const
reserve(size_t n)	Max number of elements of vector set to "n" before reallocation. Declaration: void reserve(size_t)
max_size()	Max number of elements of vector possible. Declaration: size_type max_size() const

Note: size_type is an unsigned integer.

其他 methods/operators:

Method/operator	Description
erase() clear()	Erase all elements of vector. Declaration: void clear()
erase(iterator) erase(begin_iterator,end_iterator)	Erase element of vector. Returns iterator to next element. Erase element range of vector. Returns iterator to next element. Declarations: iterator erase(iterator pos) iterator erase(iterator first, iterator last)
= Example: X=Y()	Assign/copy entire contents of one vector into another. Declaration: vector& operator=(const vector&)
<	Comparison of one vector to another. Declaration: bool operator<(const vector&, const vector&)
==	Returns bool. True if every element is equal. Declaration: bool operator==(const vector&, const vector&)
at(index) v[index]	Element of vector. Left and Right value assignment: v.at(i)=e; and e=v.at(i); Declaration: reference operator[](size_type n)
front() v[0]	First element of vector. (Left and Right value assignment.) Declaration: reference front()
back()	Last element of vector. (Left and Right value assignment.) Declaration: reference back()
push_back(const T& value)	Add element to end of vector. Declaration: void push_back(const T&)
pop_back()	Remove element from end of vector. Declaration: void pop_back()
assign(size_type n,const T& t)	Assign first n elements a value "t".
assign(begin_iterator,end_iterator)	Replace data in range defined by iterators. Declaration:
insert(iterator, const T& t)	Insert at element "iterator", element of value "t". Declaration: iterator insert(iterator pos, const T& x)
insert(iterator pos, size_type n, const T& x)	Starting before element "pos", insert first n elements of value "x". Declaration: void insert(iterator pos, size_type n, const T& x)
insert(iterator pos, begin_iterator,end_iterator)	Starting before element "pos", insert range begin_iterator to end_iterator. Declaration: void insert(iterator pos, InputIterator f, InputIterator l)
swap(vector& v2)	Swap contents of two vectors. Declaration: void swap(vector&)

遍曆vector（Iterator） methods/operators: 迭代器

Method/operator	Description
begin()	Return iterator to first element of vector. Declaration: const_iterator begin() const
end()	Return iterator to end of vector (not last element of vector but past last element) Declaration: const_iterator end() const
rbegin()	Return iterator to first element of vector (reverse order). Declaration: const_reverse_iterator rbegin() const
rend()	Return iterator to end of vector (not last element but past last element) (reverse order). Declaration: const_reverse_iterator rend() const
++	Increment iterator.
--	Decrement iterator.