題目描述
輸入兩棵二叉樹A,B,判斷B是不是A的子結構。(ps:我們約定空樹不是任意一個樹的子結構)
解析思路
實現代碼
public class Solution {
//判斷是否樹1包含樹2
public boolean doesTree1HaveTree2(TreeNode node1, TreeNode node2){
if(node2 == null){
return true;
}
if(node1 == null){
return false;
}
if(node1.val != node2.val){
return false;
}
return doesTree1HaveTree2(node1.left,node2.left)&&doesTree1HaveTree2(node1.right, node2.right);
}
public boolean HasSubtree(TreeNode root1,TreeNode root2) {
boolean result = false;
if(root1!=null && root2!=null){
if(root1.val == root2.val){
result=doesTree1HaveTree2(root1,root2);
}
if(!result){
result=HasSubtree(root1.left, root2);
}
if(!result){
result=HasSubtree(root1.right, root2);
}
}
return result;
}
}