Graph Implementation

Hi, I have to implement a graph as a adjacent matrix for my algorithms & data structure course and almost everything works correct besides method given below. The method should removes given vertex from the graph and all the edges containing it.
Returns: 0 if no error occurs or -1 otherwise
It does not produce the proper output(does not remove the given vertex and edges). I even draw and analize this step by step on a paper and I thing there is a problem with the part

if(i==vertex||j==vertex)
continue;
array[j]=matrix[j];

but I am not sure that this is the problem, maybe it is somewhere else. Please help me with this.

Code:

count - size of the adjacent matrix(number of vertices) 
adjacent[i][j] - matrix representing the graph.(from this graph vertex should be removed)

int AdjacencyMatrixGraph::removeVertex(int vertex)
{
    if(vertex>=count||vertex<0)
        return -1;
    if(count==0)
        return -1;
    else
    {
        int **tablica=new int*[count-1];
        for(int i=0;i<count-1;i++)
            tablica[i]=new int[count-1];
        
        if(!tablica)
            return -1;
        
        for(int i=0;i<count-1;i++)
            for(int j=0;j<count-1;j++)
                tablica[i][j]=0;

        for(int i=0;i<count-1;i++)
            for(int j=0;j<count-1;j++)
            {
                if(i==vertex || j==vertex)
                    continue;
                tablica[i][j]=adjacent[i][j];
                
            }

        for(int i=0; i<count;i++)
        {
            delete [] adjacent[i];
        }
        delete [] adjacent;
        
        adjacent=tablica;
        count--;
        return 0;
    }
}