remove (STL Samples)
Illustrates how to use the remove Standard Template Library (STL) function in Visual C++.
template<class ForwardIterator, class Type> inline
ForwardIterator remove(
ForwardIterator First,
ForwardIterator Last,
const T& Value
)
Remarks
注意
The class/parameter names in the prototype do not match the version in the header file. Some have been modified to improve readability.
The remove algorithm removes all elements that match value from the range (First, Last). It returns an iterator equal to Last - n, where n = number of elements removed. The last n elements of the range have undefined values. The size of the container remains the same.
Example
// 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 }
Requirements
Header: <algorithm>