remove (STL Samples)
在 Visual C++ 說明如何使用 移除 Standard Template Library (STL) 函式。
template<class ForwardIterator, class Type> inline
ForwardIterator remove(
ForwardIterator First,
ForwardIterator Last,
const T& Value
)
備註
.gif "注意事項") 注意事項 |
|---|
類別/參數名稱在原型不符合版本在標頭檔 (Header File)。修改部分以提高可讀性。 |
remove 演算法移除符合這個範圍內的所有項目 (First， Last) 的值。 它會傳回 Iterator 等於 Last -n，其中的是中的元素 n =數字移除。 這個範圍中的最後一個項目具有 n 有效，但未指定的值。 容器的大小會維持不變。
範例
// remove.cpp
// compile with: /EHsc
// Illustrates how to use the remove function.
//
// Functions:
// remove - remove all elements from the sequence that match value.
// begin - Returns an iterator that points to the first element in a
// sequence.
// end - Returns an iterator that points one past the end of a sequence.
//////////////////////////////////////////////////////////////////////
// disable warning C4786: symbol greater than 255 character,
// okay to ignore
#pragma warning(disable: 4786)
#include <iostream>
#include <vector>
#include <algorithm>
#include <functional>
using namespace std;
int 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, last;
start = Numbers.begin() ; // location of first
// element of Numbers
end = Numbers.end() ; // one past the location
// last element of Numbers
//Initialize vector Numbers
Numbers[0] = 10 ;
Numbers[1] = 20 ;
Numbers[2] = 10 ;
Numbers[3] = 15 ;
Numbers[4] = 12 ;
Numbers[5] = 7 ;
Numbers[6] = 9 ;
Numbers[7] = 10 ;
cout << "Before calling remove" << endl ;
// print content of Numbers
cout << "Numbers { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;
// remove all elements from Numbers that match 10
last = remove(start, end, 10) ;
cout << "After calling remove" << endl ;
// print content of Numbers
cout << "Numbers { " ;
for(it = start; it != end; it++)
cout << *it << " " ;
cout << " }\n" << endl ;
//print number of elements removed from Numbers
cout << "Total number of elements removed from Numbers = "
<< end - last << endl ;
//print only the valid elements of Number
cout << "Valid elements of Numbers { " ;
for(it = start; it != last; it++)
cout << *it << " " ;
cout << " }\n" << endl ;
}
Output
Before calling remove
Numbers { 10 20 10 15 12 7 9 10 }
After calling remove
Numbers { 20 15 12 7 9 7 9 10 }
Total number of elements removed from Numbers = 3
Valid elements of Numbers { 20 15 12 7 9 }
需求
Header: <algorithm>