题目描述
输入两棵二叉树A，B，判断B是不是A的子结构。（ps：我们约定空树不是任意一个树的子结构）
子结构和子树的区别
public class Solution {
public boolean HasSubtree(TreeNode root1, TreeNode root2) {
boolean result = false;
if (root1 != null && root2 != null) {
//如果这个结果相等
if (root1.val == root2.val) {
result = doesTree1HasTree2(root1, root2);
}
if (!result) {
result = HasSubtree(root1.left, root2);
}
if (!result) {
result = HasSubtree(root1.right, root2);
}
}
return result;
}
public boolean doesTree1HasTree2(TreeNode node1, TreeNode node2) {
if (node2 == null) {
return true;
}
if (node1 == null) {
return false;
}
if (node1.val != node2.val) {
return false;
}
return doesTree1HasTree2(node1.left, node2.left)
&& doesTree1HasTree2(node1.right, node2.right);
}
}
