Problem Set 1

  1. There is a Java source file at the location newproject/src/edu/gmu/ite/mantis/Mantis.java

    a. What is the name of the class defined in this file?

    b. What package does the class reside in?

  2. Find one example of each label in the following source code and write the line number of the example next to the label.

    a. Instance variable

    b. Class variable

    c. Instance method

    d. Class method

    e. Constant variable

    f. Constructor

    g. Import statement

 1:  package edu.gmu.cs.geom;
 2:  
 3:  import edu.gmu.cs.geom.Translatable;
 4:  
 5:  public class Point2d implements Translatable {
 6:  
 7:      public static int ORIGIN_X = 0;
 8:      public static int ORIGIN_Y = 0;
 9:  
10:      private int x;
11:      private int y;
12:  
13:      public Point2d() {
14:          this.x = Point2d.ORIGIN_X;
15:          this.y = Point2d.ORIGIN_Y;
16:      }
17:  
18:      public Point2d(int x, int y) {
19:          this.x = x;
20:          this.y = y;
21:      }
22:  
23:      public int getX() {
24:          return this.x;
25:      }
26:  
27:      public int getY() {
28:          return this.y;
29:      }
30:  
31:      public void translate(int xDelta, int yDelta) {
32:          this.x += xDelta;
33:          this.y += yDelta;
34:      }
35:  
36:      public static Point2d add(Point2d left, Point2d right) {
37:          int x = left.getX() + right.getX();
38:          int y = left.getY() + right.getY();
39:  
40:          return new Point2d(x, y);
41:      }
42:  
43:  }
  1. Order the following code segments by time complexity in ascending order. For bonus points, show the runtime of each code segment in Big O notation.

a.

for (int y = 0; y < n; y++) {
    for (int x = 0; x < n; x++) {
        m[y, x] = 0;
    }
}

b.

public boolean isOdd(int x) {
    return (x % 2) == 0;
}

c.

int x = 0;
int y = 0;

while (x < MAX) {
    if (isOdd(x)) {
        x++;
        y++;
    } else {
        x++;
    }
}

d.

int sum = 0;
for (int i = 0; i < items.size(); i = (i * 2) + 1) {
    sum += items.get(i);
}

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