给定一个二叉树,检查它是否是镜像对称的。
例如,二叉树 [1,2,2,3,4,4,3] 是对称的。
1
/ \
2 2
/ \ / \
3 4 4 3
但是下面这个 [1,2,2,null,3,null,3] 则不是镜像对称的:
1
/ \
2 2
\ \
3 3
class Nodes{
int var;
Nodes left;
Nodes right;
public Nodes(int var){
this.var=var;
}
}
public class DuiChengTree {
public static void main(String[] args) {
Nodes nodes=new Nodes(1);
Nodes nodes1=new Nodes(2);
Nodes nodes2=new Nodes(3);
nodes1.left=nodes;
nodes1.right=nodes2;
System.out.println(getTree(nodes1));
}
public static boolean getTree(Nodes nodes){
if (nodes==null){
return false;
}
return is(nodes.left,nodes.right);
}
public static boolean is(Nodes left, Nodes right){
if (left==null&&right==null){
return true;
}
if (left==null||right==null){
return false;
}
return ((left.var==right.var)&&is(left.left,left.right)&&is(right.left,right.right));
}
}