Pointer to array of pointers pointing to nodes

I want to create a pointer to an array of pointers, and that pointer inside the array points to nodes.

CodePudding user response：

Maybe you can try to image 2D points nodes array as 1D vector. That will help you image this question.

If you want to set many groups nodes coordinate

Group 1: node1X,node1Y,node2X,node2Y,node3X,node3Y .........

Group 2: node1X,node1Y,node2X,node2Y,node3X,node3Y .........

Group 3: node1X,node1Y,node2X,node2Y,node3X,node3Y .........

.......

void main()
{
//5 groups,each group have 4 nodes
int ** groups;
groups = new int*[5];
for (int i = 0; i < 5; i  ) groups[i] = new int[4 * 2];
//set
for (int i = 0; i < 5; i  )
{
    for (int j = 0; j < 4; j  )
    {
        groups[i][j * 2] = j;
        groups[i][j * 2   1] = j;
    }
}
//printf
for (int i = 0; i < 5; i  )
{
    printf("Grop[%d]:", i);
    for (int j = 0; j < 4; j  )
    {
        printf("node[%d]X=%d ", j, groups[i][j*2] );
        printf("node[%d]Y=%d ,", j, groups[i][j*2 1]);
    }
    printf("\n");
}
for (int i = 0; i < 5; i  ) delete groups[i];
delete groups;
system("pause");
}

Remember to delete memory!

Print result sample

CodePudding user response：

you mean data_type **identifier, you could n dimension in your array declaration.

data_type **identifier = malloc(sizeof(data_type))

then for example assigning the first element of this array could be.

identifier[0] = malloc(size_of_this_array * sizeof(data_type))