100. Same Tree

https://leetcode-cn.com/problems/same-tree/

https://leetcode-cn.com/problems/same-tree/

（图片来源https://leetcode-cn.com/problems/same-tree/

）

public boolean isSameTree(TreeNode p, TreeNode q) {

        if(p == null || q == null) {
            return p == null && q == null;
        }

        if(p.val != q.val) {
            return false;
        }

        return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
    }

非递归

public boolean isSameTree(TreeNode p, TreeNode q) {
        Queue<TreeNode[]> nodesQ = new LinkedList<>();
        nodesQ.offer(new TreeNode[]{p, q});

        while(!nodesQ.isEmpty()) {
            TreeNode[] nodes = nodesQ.poll();
            if(nodes[0] == null || nodes[1] == null) {
                if(nodes[0] == nodes[1]) {
                    continue;
                }

                return false;
            }
            if(nodes[0].val != nodes[1].val) {
                return false;
            }

            nodesQ.offer(new TreeNode[]{nodes[0].left, nodes[1].left});
            nodesQ.offer(new TreeNode[]{nodes[0].right, nodes[1].right});
        }

        return true;
    }