passing reference of 2d vector of characters

[dannyboy13872]

Hi everyone,
So far, I have only used a 2d array for a matrix. I was given the declaration of the vector as,

vector<vector<char> > A (N,(vector<char> (N)));

I have tried every way I can think of to pass the vector as a referenced argument, but I am getting nowhere. I am having other errors, pointer arithmetic, but with time I can figure it out I think. The main concern I have is the argument. Can anyone point me in the right direction, everything I have found points to this being correct, but obviously it is not.

#include <iostream>
#include <vector>
using namespace std;


void inPlaceRotate(vector<vector<char> > &B(),int N){
   // int N = B->size();
    for(int i=0; i < N/2; i++)
        for(int j=0; j < (N+1)/2; j++){
            char temp = B[i][j];
            B[i][j] = B[N-j-1][i];
            B[N-j-1][i] = B[N-i-1][N-j-1];
            B[N-1-i][N-1-j] = d[j][N-1-i];
            B[j][N-1-i] = temp;
        }

}




int main()
{

    //ios_base::sync_with_stdio(false);
    //cin.tie(NULL);
    int n, N;

    cin >> N >> n;
    while(!(n ==0) && !(N ==0)){
      //read in and store larger matrix
        vector<vector<char> > A (N,(vector<char> (N)));
        for(int row = 0; row < N; row++){
            for(int col = 0; col < N; col++){
                cin >> A[row][col];
             
            }
        }
        //store smaller matrix
        vector<vector<char> > B(n,(vector<char> (n)));
        for(int row = 0; row < n; row++){
            for(int col =0;col < n; col++){
                cin >> B[row][col];
            
            }
        }
        //print matrix
          for(int row = 0; row < n; row++){
            for(int col =0;col < n; col++){
                cout << B[row][col];
                
            }
        }

        cin >> n;
    }
    return 0;
}

[Ganado]

When you passed your int by value, you wrote on line 6
int N

If you were to pass your int by reference, you would write
int& N

If you want to pass an arbitrary type by reference, you'd write something like
T& t

vectors are not special in this regard, just drop the parentheses.

void inPlaceRotate(vector<vector<char> > &B){
    B.size();
}

[Repeater]

void inPlaceRotate(vector<vector<char> > &B(),int N){
should be
void inPlaceRotate(vector<vector<char> > &B,int N){

[dannyboy13872]

Thank you very much, I understand vector's make a lot of things easier. I just need to learn the correct usage. Thank you

[jonnin]

this might be a good place to typedef or similar the annoying double vector syntax rather than repeat it everywhere. /shrug

[Thomas1965]

this might be a good place to typedef or similar the annoying double vector syntax rather than repeat it everywhere. /shrug

Yes very good idea.

using Matrix = vector<vector<char>>;

void do_work(Matrix& m)
{

}