Question

所以我正在研究一种方法，我有点困惑，重点是将学生分成一个基于id号码的列表，以便id值较低的学生先来等等...我很困惑什么一旦我检查它是否更大，在我的if语句内做。

我现在的代码是

public boolean insort(StudentIF s) {
    StudentLLNode curr = head;

    if (s == null) {
        return false;
    }
    if (head == null) {
        StudentLLNode student = new StudentLLNode(s);
        head = student;
        size++;
        //System.out.println("working");
        return true;
    } else {
        if (curr.getStd().compareTo(s) == 0) {
            //System.out.println("working");
            return false;
        }
        while (curr.getNext() != null) {
            if(s.compareTo(curr.getStd()) == 1){
                //confused here 
            }
            curr = curr.getNext();
        }
        //confused here
        StudentLLNode student1 = new StudentLLNode(s);
        curr.setNext(student1);
        size++;
        return true;
    }
}

我与方法的比较是

public int compareTo(StudentIF other) {
    if (other == null) {
        return 1;
    } // satisfies null student
    if (this.id > other.getId())
        return 1;
    else if (this.id < other.getId())
        return -1;
    else
        return 0; // if it's neither smaller nor larger, it must be equal
}

Answer 1

int index = Collections.binarySearch(myStudentList, studentObject);
myStudentList.add(index < 0 ? -1 * (index + 1) : index, studentObject);
/* OR
if(index < 0)
    myStudentList.add(-1 * (index + 1), studentObject);
If you did not want to add duplicates
*/

二进制搜索返回studentObject的索引，如果对象不在列表中，则返回-(insertIndex) - 1。

根据身份证号码将学生插入列表

1 个答案: