非递归先,中,后遍历二叉树

1:后序遍历二叉树

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//后序遍历二叉树,在函数中改变了树T,可以在函数中对原树Ｔ进行复制然后处理复制树或者加些辅助结构 public static void InOrderTraverse(Tree T,Tree r){ Stake stake = new Stake(); //栈 stake.push(T); Tree tem = T; while (!stake.isEmpty()){ while (tem!= null && tem.lchild != null ){ //向左走到尽头,等于访问根的左子树=null stake.push(tem.lchild); tem = tem.lchild; } tem = tem.rchild; //访问右子树 if (tem != null )stake.push(tem); else { //一个节点的左子树和右子树都为null的情况,即表明该根节点的左右子树均已经被访问过了,现在访问根节点 tem = stake.pop(); System.out.print(tem.ele+ " " ); //访问根节点 tem = stake.peek(); if (tem == null ) return ; //遍历结束 if (tem.lchild != null )tem.lchild = null ; //如果左子树被访问,设置其左为null，在此处改变了树 else tem.rchild = null ; //同理,设置其右为null } } }

2:先序和中序遍历二叉树

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//非递归方法遍历二叉树,中序遍历      public  static  void  InOrderTraverse(Tree T){          Stake stake =  new  Stake();          stake.push(T);          Tree tem = T;                    while (!stake.isEmpty()){              while (tem!= null  && tem.lchild !=  null ){ //向左走到尽头                  stake.push(tem.lchild);                  tem = tem.lchild;              }                            tem = stake.pop();              System.out.print(tem.ele+ " " ); //访问根节点                            tem = tem.rchild; //访问右子树              if (tem !=  null )stake.push(tem);          }      }            //非递归方法遍历二叉树二          public  static  void  InOrderTraverse2(Tree T){              Stake stake =  new  Stake(); //栈道              //stake.push(T);              Tree tem = T;              boolean  flag =  true ;                            while (flag || !stake.isEmpty()){                  flag =  false ;                                    if (tem !=  null ){                      System.out.println(tem.ele+ " " ); //先序遍历法                      stake.push(tem); tem = tem.lchild; //遍历左子树                  }                  else {                      tem = stake.pop();                      //System.out.print(tem.ele+" ");//中序遍历法访问根节点                      tem = tem.rchild; //遍历右子树                  }              }          }