java递归mergesort只返回ArrayList的前半部分

Question

对于CS作业，我尝试使用合并排序方法对ArrayList进行排序。这是我的密码：

public static LinkedList<Object> merge (LinkedList<Object> lsta, LinkedList<Object> lstb) {
    LinkedList<Object> result = new LinkedList<Object>();
    LinkedList<Object> lstaNew = (LinkedList<Object>) lsta.clone();
    LinkedList<Object> lstbNew = (LinkedList<Object>) lstb.clone();
    while(lstaNew.size()>0||lstaNew.size()>0) {
        if(lstaNew.size()>0&&lstbNew.size()>0) {
            if( ((Comparable) lstaNew.getFirst()).compareTo(lstbNew.getFirst()) < 0 ) {
                result.add(lstaNew.getFirst());
                lstaNew.remove();
            }
            else {
                result.add(lstbNew.getFirst());
                lstbNew.remove();
            }
        }
        else if(lstaNew.size()>0) {
            result.add(lstaNew.getFirst());
            lstaNew.remove();
        }
        else {
            result.add(lstbNew.getFirst());
            lstbNew.remove();
        }
    }
    return result;
}

public static LinkedList<Object> sort (LinkedList<Object> lst) {
    if (lst.size() <= 1) return lst;
    LinkedList<Object> left = new LinkedList<Object>();
    LinkedList<Object> right = new LinkedList<Object>();
    int midpoint = lst.size()/2;
    for (int i=0;i<midpoint;i++) left.add(lst.get(i));
    for (int i=midpoint;i<lst.size();i++) right.add(lst.get(i));
    return merge(sort(left),sort(right));
}

然而，在我的结果中，我只得到了列表的前一半。我在网上查看了其他合并排序示例，我的代码似乎与之类似。我做错了什么？如果能给我一个指向正确方向的指针，我将不胜感激

Answer 1

您的代码中有一个输入错误-

while(lstaNew.size()>0||lstaNew.size()>0) {

本应是—

while(lstaNew.size()>0||lstbNew.size()>0) {