what is this doing??

[modtheplanet]

I have been looking at code for a magic square problem and have no idea what this code is doing. Could you guys please help me?

for (count = 2; count <= max_count; count++)
    {
    row = (i - 1 < 0) ? (size - 1) : (i - 1);  // up
    col = (j - 1 < 0) ? (size - 1) : (j - 1);  // left


//i know what this is doing just need help with the above


    if (square[row][col] != 0)
      {
      i ++;
      i = i % size;
      }
    else
      {
      i = row;
      j = col;
      }
    square[i][j] = count;
    }

[axon]

its another way of saying if else...

[Salem]

As in

if ( i - 1 < 0 ) {
  row = size - 1;
} else {
  row = i - 1;
}