测试遍历二叉搜索树（BST）

Question

What is a good way to test the in-order traversal of a binary search tree with Google Test? I can test it manually by printing out the values of the nodes and verifying that the list is sorted visually. Is there a way to validate this automatically using Google Test? I was thinking of adding a static string to the node class and appending to the string for every node visited. The problem with this is that there could be multiple trees which should each have their own in-order list but there can only be one static string.

Once I get it working with the in-order traversal the solution should be extensible to pre-order and post-order traversals.

Answer 1

Keep track of the previous entry and when you're no longer on the first entry.

Assert that you're still on the first entry or the current entry is >= the previous entry.