Remove Elements from Vector

Hi

I am trying to remove elements from vector "clusters" if they exist in vector "removeCluster".

Any help is appreciated.

--------------------------------------------------------------------

#include <iostream>
#include <string>
#include <vector>

int main()
{
vector<int> clusters;
vector<int> removeClusters;

for (int i = 0; i < 10; i++)
{
clusters.push_back(i);
}

for (int i = 0; i < (clusters.size() ) ; i++)
{
cout << "Cluster Vector " << clusters[i] << endl;
}

removeClusters.push_back(3);
removeClusters.push_back(1);
removeClusters.push_back(11);

for (int i = 0; i < (removeClusters.size() ) ; i++)
{
cout << "Remove Cluster Vector " << removeClusters[i] << endl;
}


// update remain cluster vector
for (int i = 0; i < clusters.size(); i++)
{
for (int j = 0; j < removeClusters.size(); j++)
{
if ( removeClusters[j] == clusters[i] )
{
cout << " Found " << clusters[i] << endl;

}
}
}

return 0;

}

To remove all elements of a certain value from a vector or string,
you use the "erase-remove" idiom (requires #include <algorithm>):

Code:

---

v.erase( std::remove( v.begin() , v.end() , VALUE_TO_REMOVE ) , v.end() );

---

So for your case, you could do the following:

Code:

---

for (int j = 0; j < removeClusters.size(); ++j)
{
  clusters.erase( std::remove(clusters.begin(),clusters.end(),removeClusters[j]) , clusters.end() );
}

---

Note: erasing from a vector is expensive, so if the
vector to remove from is large, this could be time
consuming. If that is the case,you would need to
explore alternative container solutions.

remove() does not delete one or more elements from a vector. It moves one or more elements to the end of the vectors. For removal and deallocation, use erase() as mentioned.

Kuphryn