/** public class TreeNode { int val = 0; TreeNode left = null; TreeNode right = null; public TreeNode(int val) { this.val = val; } } */ public class Solution { public boolean HasSubtree(TreeNode root1, TreeNode root2) { if (root1 == null || root2 == null) return false; if (sameTree(root1, root2)) { return true; } else { return HasSubtree(root1.left, root2) || HasSubtree(root1.right, root2); } } private boolean sameTree(TreeNode root1, TreeNode root2) { if (root2 == null) return true; if (root1 != null && root2 != null) { if (root1.val == root2.val) { return sameTree(root1.left, root2.left) && sameTree(root1.right, root2.right); } else { return false; } } return false; } }
算法思想:递归判断根节点+递归判断左右子树