//定义树节点
public static class TreeNode{
int val;TreeNode leftchild;
TreeNode rightchild;
public TreeNode(int data){
this.val = data;
}
}
//创建二叉树,并且返回根节点
public TreeNode createBTree(){
TreeNode root = null;
List<TreeNode> nodelist = new ArrayList<TreeNode>();
//循环创建结点,并添加到nodeList表中
for(int i = 0; i < array.length; i++){
nodelist.add(new TreeNode(array[i]));
}
/*将结点存放在对应父节点的左右子树上,其边初试结点从j=0开始,
* 则左子树结点为2*j+1,右子树结点为2*j+2,
* 边界条件是array.length-1
*/
for(int j = 0; j < array.length/2-1; j++){
nodelist.get(j).leftchild = nodelist.get(2*j+1);
nodelist.get(j).rightchild = nodelist.get(2*j+2);
}
//考察特殊点的处理
int temp = array.length/2-1;
nodelist.get(temp).leftchild = nodelist.get(2*temp+1);
nodelist.get(temp).rightchild = nodelist.get(2*temp+2);
root=nodelist.get(0);
return root;}