100. Same Tree
Given two binary trees, write a function to check if they are the same or not.
Two binary trees are considered the same if they are structurally identical and the nodes have the same value.
Example 1:
Input: 1 1 / \ / \ 2 3 2 3 [1,2,3], [1,2,3] Output: true
Example 2:
Input: 1 1 / \ 2 2 [1,2], [1,null,2] Output: false
Example 3:
Input: 1 1 / \ / \ 2 1 1 2 [1,2,1], [1,1,2] Output: false
二叉树有三种遍历方式,先序遍历,中序遍历以及后序遍历
采用中序遍历,进行逐结点进行比较
只要写出比较一个结点的方法就可以,然后递归调用左右子结点。
public bool IsSameTree(TreeNode p, TreeNode q) { bool flag; if (p == null && q == null) { flag = true; } else if (p == null || q == null) { flag = false; } else { if (p.val == q.val) { flag = IsSameTree(p.left, q.left) && IsSameTree(p.right, q.right); } else { flag = false; } } return flag; }