Diagonal Difference

/*
 * Complete the 'diagonalDifference' function below.
 *
 * The function is expected to return an INTEGER.
 * The function accepts 2D_INTEGER_ARRAY arr as parameter.
 */

int diagonalDifference(vector<vector<int>> arr) {
    
    int LeftToRight = 0;
    int RightToLeft = 0;
    
    for(int i = 0; i < arr.size(); i++){
        LeftToRight += arr[i][i];
        //cout << arr[i][i] << " ";
    }
    cout << endl;
    for(int k = arr.size() - 1 ; k >= 0 ; k-- ){
        RightToLeft += arr[arr.size()-1-k][k];
        //cout << arr[arr.size()-1-k][k] << " ";
    }
    
    return abs(LeftToRight - RightToLeft);
    
}