CSCI A201/A597

Lecture Notes 12

Spring 2000

In which we review the material for the practical.

The grid: 
public class Practical {
  public static void main(String[] args) {
    int size = Integer.parseInt(args[0]), i, j;

    for (i = 0; i < size; i++) {
      for (j = 0; j < size; j++) {
        if (false) {
          System.out.print("*"); 
        } else { 
          System.out.print(" "); 
        } 
      }
      System.out.println(); 
    }
  }
}

Pattern 1:

Pattern 2: 

(j == 0)
 
(i == 0)
Pattern 3:

Pattern 4: 

(j == (size - 1))
 
(i == (size - 1))
Pattern 5:

Pattern 6: 

((j == 0) && (i <= size/2))
 
((j == 0) && (i > size/2))
Pattern 7:

Pattern 8: 

((i == 0) && (j <= size/2))
 
((i == 0) && (j > size/2))

Pattern 9: ((j == (size - 1)) && (i <= size/2))

Pattern 10: ((j == (size - 1) && (i > size/2))

Pattern 11: ((i == (size - 1)) && (j < size/2))

Pattern 12: ((i == (size - 1)) && (j > size/2)

Pattern 13:

Pattern 14: 

(j == size/2)
 
(i == size/2)
Pattern 15:

Pattern 16:

15: ((j == size/2) && (i <= size/2))
16: ((j == size/2) && (i > size/2))

Pattern 17:

Pattern 18:

17: ((i == size/2) && (j <= size/2))
18: ((i == size/2) && (j > size/2))

Pattern 19:

Pattern 20: 

(i == j)
 
(i + j == (size - 1))
Pattern 21:

Pattern 22:

21: ((i == j) && (i <= size/2) && (j <= size/2))
22: ((i == j) && (i > size/2) && (j > size/2))

Can either one of these conditions be simplified at all?

Pattern 23:

Pattern 24:

23: ((i + j == (size - 1)) && (i <= size/2) && (j > size/2))
24: ((i + j == (size - 1)) && (i > size/2) && (j <= size/2))

Can either one of these be simplified?

In class we will discuss these "atomic" patterns, and how we can combine them to obtain more complicated patterns such as these:

Uppercase T: A cell should be turned ON if it appears in the group described by pattern 13 OR if it appears in the group that is described by pattern 2 Uppercase L: A cell should be turned ON if it appears in the group described by pattern 13 OR if it appears in the group described by pattern 12
Uppercase E: if cell is in pattern 1 OR in pattern 2 OR in pattern 4 or in pattern 17 then the cell should be turned ON otherwise leave the cell blank (print a space) Uppercase W: cell turned ON if pattern 1 matches OR pattern 24 matches OR pattern 22 matches OR pattern 3 matches
Uppercase A: (20) OR (3) OR (18) Uppercase R: (22) || (1) || (14) || (2) || (9)

Last updated on Feb 17, 2000 by Adrian German