How do you print a 2D array given a data access table and a 1D array of the data?

Question

If I have a 1 dimensional array of data such as this:

1 2 3 4 5 6 7 8 9 1

and a corresponding data access table:

0 2 5 8

How would I print the 2D diagonalized array below with the zeros?

1 2 0 0
3 4 5 0
0 6 7 8
0 0 9 1

Code would be very helpful. Thanks

Here is what I tried...the if statement needs tweaking:

//table[] is the access table
//data[] is the 1D array
//grid[][] is the 2D array

  for(row=0; row<sideSize; row++)
    for(col=0; col<sideSize; col++){
      if(col < table[col+1] - table[col]-1)
        grid[row][col] = data[col+row];
      else
        grid[row][col] = 0;
    }

Here is the entire function so far:

void printMatrix(int* table, int* data, int diagonals, int arraySize, int sideSize){
  int** grid;
  int row, col, i;

  grid = (int**)malloc(sizeof(int)*sideSize);
  for(i=0; i<sideSize; i++)
    grid[i] = (int*)malloc(sizeof(int)*sideSize);

  printf("\n");

  for(row=0; row<sideSize; row++)
    for(col=0; col<sideSize; col++){
      if(col < table[col+1] - table[col]-1)
        grid[row][col] = data[col+row];
      else
        grid[row][col] = 0;
    }

  for(row=0; row<sideSize; row++){
    for(col=0; col<sideSize; col++)
      printf("%d ", grid[row][col]);
    printf("\n");
  }

  for(i=0; i<sideSize; i++)
    free(grid[i]);
  free(grid);

  free(table);
  free(data);
}

Alok your method of printing the middle rows won't work for this matrix for example:

9 7 5 0 0 0 0 0 0
8 9 7 5 0 0 0 0 0
5 8 9 7 3 0 0 0 0
0 5 8 9 7 3 0 0 0
0 0 3 8 9 7 5 0 0
0 0 0 3 8 9 7 5 0
0 0 0 0 5 8 9 7 8
0 0 0 0 0 5 8 9 9
0 0 0 0 0 0 8 9 9

Answer 1

The data access table just tells you where each row of data is put in the 1D array. So the 1 2 in the first row starts at index 0. The 3 4 5 in the second row starts at index 2. The 6 7 8 in the third row starts at index 5 and so on...

This sounds good but your example:

1 2 0 0

3 4 5 0

0 6 7 8

0 0 9 1

I don't see the 3 4 5 starting at index two. Please explain.

Answer 2

Ok, I found a way to print the matrix using the data access table. You can do it by starting from the middle row(s) (for even matrices there are 2 middle rows) of the matrix (since it is symmetric) and calculating the padding of zeros which will have the same number on both sides. Then you just decrement that value for the rows above the middle row and increment for each row below it (on the left side). Then you use the access table to insert the data elements for that row. Finally add zeros to the right side of the data for each row.

Thanks for your suggestions!