剑指Offer(Java版)第二十二题：输入两棵二叉树A和B，判断B是不是A的子结构。

/*
输入两棵二叉树A和B，判断B是不是A的子结构。
*/
//解题思路：
//1）对A进行遍历，寻找B的根子节点
//2）接着在A中寻找是否含有B的结构。
public class Class22 {

static class TreeNode{
double val;
TreeNode left = null;
TreeNode right = null;
public TreeNode(int val){
this.val = val;
}
}

public boolean hasSubTree(TreeNode tree1, TreeNode tree2){
boolean result = false;
if((tree1 == null) || (tree2 == null)){
return false;
}
if((tree1 != null) && (tree2 != null)){
if(tree1.val == tree2.val){
result = doseTree1HasTree2(tree1,tree2);
if(!result){
result = hasSubTree(tree1.left,tree2) || hasSubTree(tree1.right,tree2);
}
}
}
return result;
}

public boolean doseTree1HasTree2(TreeNode tree1, TreeNode tree2){
if(tree1 == null){
return false;
}
if(tree2 == null){
return true;
}
if(tree1.val == tree2.val){
return true;
}
if(tree1.val != tree2.val){
return false;
}
return doseTree1HasTree2(tree1.left,tree2.left) && doseTree1HasTree2(tree1.right,tree2.right);
}

public static void main(String[] args) {
// TODO Auto-generated method stub

}

}

原文：https://www.cnblogs.com/zhuozige/p/12465467.html