[leetcode] 100. Same Tree 解题报告

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

空值判断+递归

public boolean isSameTree(TreeNode p, TreeNode q) {
        if ((p == null && q != null) || (p != null && q == null)) return false;
        else if (p == null && q == null) return true;
        else  {
            if (p.val != q.val) { return  false; }
            else {
                return ( isSameTree(p.left, q.left) && isSameTree(p.right, q.right) );
            }
        }
    }