remove
Removes elements with a given value
You're viewing an older version of this page (#5939). View the current version.
Definition
The remove() algorithm is defined in the standard header <algorithm> and in the nonstandard backward-compatibility header <algo.h>.
Interface
#include <algorithm>
template < class ForwardIterator, class Type >
ForwardIterator remove(
ForwardIterator first,
ForwardIterator last,
const Type& val
);Parameters:
| Parameter | Description |
| first | A forward iterator addressing the position of the first element in the range from which elements are being removed |
| last | A forward iterator addressing the position one past the final element in the range from which elements are being removed |
| val | The value that is to be removed from the range |
Description
Remove algorithm removes all elements that are equal to val from the range [first, last). (Uses operator== to compare elements.)
Remove is stable, meaning that the relative order of elements that are not equal to val is unchanged.
Return Value
Returns a forward iterator to the new end of the range (one past the last element not removed), or first if first and last are equal.
Complexity
The complexity is linear; performs (last - first) comparisons for equality.
References
Example 1
This program illustrates the functionality of remove() algorithm.
#include <vector>
#include <algorithm>
#include <iostream>
using namespace std;
int main()
{
vector <int> vec1;
vector <int>::iterator Iter1, new_end;
int i,j;
for (i = 1; i <= 10; i++)
vec1.push_back(i);
for (j = 0; j <= 2; j++)
vec1.push_back(8);
cout <<"Vector vec1 original data: is\n";
for (Iter1 = vec1.begin(); Iter1 != vec1.end(); Iter1++)
cout <<*Iter1<<" ";
cout <<endl;
random_shuffle(vec1.begin(), vec1.end());
cout <<"Vector vec1 random shuffle data is:\n";
for (Iter1 = vec1.begin(); Iter1 != vec1.end(); Iter1++)
cout <<*Iter1<<" ";
cout <<endl;
// remove elements with a value of 8
new_end = remove(vec1.begin(), vec1.end(), 8);
cout <<"Vector vec1 data with value 8 removed is:\n";
for (Iter1 = vec1.begin(); Iter1 != vec1.end(); Iter1++)
cout <<*Iter1<<" ";
cout <<endl;
// using erase, to change the sequence size
vec1.erase(new_end, vec1.end());
cout <<"Vector vec1 resized data with value 8 removed is:\n";
for (Iter1 = vec1.begin(); Iter1 != vec1.end(); Iter1++)
cout <<*Iter1<<" ";
cout <<endl;
return 0;
}Output:
Vector vec1 original data:
1 2 3 4 5 6 7 8 9 10 8 8 8
Vector vec1 random shuffle data is:
8 2 10 3 1 8 8 4 5 7 9 6 8
Vector vec1 data with value 8 removed is:
2 10 3 1 4 5 7 9 6 7 9 6 8
Vector vec1 resized data with value 8 removed is:
2 10 3 1 4 5 7 9 6