LeetCode 572 另一棵树的子树

方法1：DFS + 暴力匹配

class Solution {
    public boolean isSubtree(TreeNode root, TreeNode subRoot) {
        if(root == null) return false;
        return isSameTree(root, subRoot) || isSubtree(root.left, subRoot) || isSubtree(root.right, subRoot);
    }

    static boolean isSameTree(TreeNode s, TreeNode t) {
        if(s == null && t == null) return true;
        if(s == null || t == null || s.val != t.val) return false;
        return isSameTree(s.left, t.left) && isSameTree(s.right, t.right);
    }
}