// Code for CS1Ah Note 19: Supporting Queries.
// November 2002.

// Barebones StudentCollection class, similar to ClassOfStudents examples
// from Using Arrays lecture.

public class StudentCollection {
  private static final int N = 1000;
  private Student[] members;
  private int number;

  public StudentCollection() {
    members = new Student[N];
    number = 0;
  }
  public boolean insert(Student newStudent) {
    if (number == N)
      return false;
    else {
      members[number] = newStudent;
      number++;
      return true;
    }
  }
  public String toString() {
    String res = new String();
    for (int i = 0; i < number; i++) {
      res = res + i + "." + members[i] + "\n";
    }
    return res;
  }
  public StudentCollection select1() {
    StudentCollection res = new StudentCollection();
    for (int i = 0; i < number; i++) {
      if (members[i].property1()) {
        res.insert(members[i]);
      }
    }
    return res;
  }
  public StudentCollection select2(String basicProperty) {
    StudentCollection res = new StudentCollection();
    for (int i = 0; i < number; i++) {
      if (members[i].hasBasicProperty(basicProperty)) {
        res.insert(members[i]);
      }
    }
    return res;
  }
  public StudentCollection select3(String[] conjunctiveProperty) {
    StudentCollection res = new StudentCollection();
    for (int i = 0; i < number; i++) {
      if (members[i].hasConjunctiveProperty(conjunctiveProperty)) {
        res.insert(members[i]);
      }
    }
    return res;
  }
  public StudentCollection select4(String[][] dnfProperty) {
    StudentCollection res = new StudentCollection();
    for (int i = 0; i < number; i++) {
      if (members[i].hasDnfProperty(dnfProperty)) {
        res.insert(members[i]);
      }
    }
    return res;
  }

}