如何删除2d向量中的列，c ++

Question

If i have a vector inside a vector creating a matrix, how do I delete a specific column in that matrix. I have already populated the 2d vector now i need a method to delete a specific column in that vector,

for example my vector would look like:

vector<vector<float> > vec;

Just for knowledge i know how to erase the rows in the vector as below:

vec.erase(vec.begin()+row);

// so What is the algorithm or code to delete a specific column in a vector of vector

for example if i have

V11, V12, V13
V21, V22, V23
V31, V32, V33

Then I would like to remove a specific column for instance column 1 which will erase V12, V22, V32 and shrink as below:

V11, V13
V21, V23
V31, V33

Thank you for looking at this problem.

Answer 1

You'll need to loop through all the rows, and delete the element in that column in each row.

int columnIndex = 1;
std::for_each(vec.begin(), vec.end(), 
    [&](std::vector<float>& row) {
        row.erase(std::next(row.begin(), columnIndex));
    });

Live demo