CS 61B homework5

part one two

提醒注意cast的地方：

这里如果不cast就用不了newNode

Comparable cast

注意sentinel的myList也是null

注意有很多地方都要用到InvalidNodeException，就在那个函数处catch就好，不要throw到main不然无法继续进行while里面语句。（给自己的tip：左边标号栏error有时候显示和光标处不同，先改鼠标移动出现的光标处错误）

  public void insert(Comparable c) {
    // Your solution here.
      try{                   
      if(NewSet.isEmpty()){
          NewSet.insertBack(c);
      }else{    
          ListNode CurrentNode = NewSet.front();
          while(true){            
              Comparable CurrentItem = (Comparable) CurrentNode.item();
              if(c.compareTo(CurrentItem)<0){
                  CurrentNode.insertBefore(c);
                  break;
              }else if(c.compareTo(CurrentItem)==0){
                  break;
              }else if(!CurrentNode.next().isValidNode()){
                  CurrentNode.insertAfter(c);
                  break;
              }
              CurrentNode=CurrentNode.next();
              }                   
              }
          }catch(InvalidNodeException e){System.err.println(e);}
      
  }

  /**
   *  union() modifies this Set so that it contains all the elements it
   *  started with, plus all the elements of s.  The Set s is NOT modified.
   *  Make sure that duplicate elements are not created.
   *
   *  Performance:  Must run in O(this.cardinality() + s.cardinality()) time.
   *
   *  Your implementation should NOT copy elements of s or "this", though it
   *  will copy _references_ to the elements of s.  Your implementation will
   *  create new _nodes_ for the elements of s that are added to "this", but
   *  you should reuse the nodes that are already part of "this".
   *
   *  DO NOT MODIFY THE SET s.
   *  DO NOT ATTEMPT TO COPY ELEMENTS; just copy _references_ to them.
   **/
  public void union(Set s) {
    // Your solution here.
      if(s.cardinality()==0){return;}
      else if(this.cardinality()==0){this.NewSet=s.NewSet;this.head=s.head;}
      
      ListNode CurrentSNode = s.NewSet.front();
      ListNode CurrentThisNode = this.NewSet.front();
      try{
      while(CurrentSNode.isValidNode()&&CurrentThisNode.isValidNode()){
          Comparable SItem = (Comparable) CurrentSNode.item();
          Comparable ThisItem = (Comparable) CurrentThisNode.item();
          if(SItem.compareTo(ThisItem)<0){
              CurrentThisNode.insertBefore(SItem);
              CurrentSNode=CurrentSNode.next();
          }else if(SItem.compareTo(ThisItem)==0){
              CurrentSNode=CurrentSNode.next();
//              CurrentThisNode=CurrentThisNode.next();
          }else if(SItem.compareTo(ThisItem)>0){
              if(CurrentThisNode.next().isValidNode()){
              CurrentThisNode=CurrentThisNode.next();
              }else{
                  CurrentThisNode.insertAfter(SItem);
                  CurrentThisNode=CurrentThisNode.next();
                  CurrentSNode = CurrentSNode.next();
              }
          }
      }
      }catch(InvalidNodeException e1){System.err.println(e1);}
      
  }

  /**
   *  intersect() modifies this Set so that it contains the intersection of
   *  its own elements and the elements of s.  The Set s is NOT modified.
   *
   *  Performance:  Must run in O(this.cardinality() + s.cardinality()) time.
   *
   *  Do not construct any new ListNodes during the execution of intersect.
   *  Reuse the nodes of "this" that will be in the intersection.
   *
   *  DO NOT MODIFY THE SET s.
   *  DO NOT CONSTRUCT ANY NEW NODES.
   *  DO NOT ATTEMPT TO COPY ELEMENTS.
   **/
  public void intersect(Set s) {
    // Your solution here.
      if(s.cardinality()==0){
          this.NewSet=s.NewSet;
          head=s.head;
          }
      if(this.cardinality()==0){return;}
      
      
      ListNode CurrentSNode = s.NewSet.front();
      ListNode CurrentThisNode = this.NewSet.front();
      try{
      while(CurrentSNode.isValidNode()&&CurrentThisNode.isValidNode()){
          Comparable SItem = (Comparable) CurrentSNode.item();
          Comparable ThisItem = (Comparable) CurrentThisNode.item();
          if(SItem.compareTo(ThisItem)==0){
              CurrentSNode=CurrentSNode.next();
              CurrentThisNode=CurrentThisNode.next();
          }else if(SItem.compareTo(ThisItem)<0){
              CurrentSNode=CurrentSNode.next();
          }else{
              if(!CurrentThisNode.next().isValidNode()){
                  return;
              }
              CurrentThisNode=CurrentThisNode.next();
              CurrentThisNode.prev().remove();
          }

      }
      }catch(InvalidNodeException e1){System.err.println(e1);}
  }