标签：efi arch int div 分析 process sub prot struct
Validate Binary Search Tree
Given a binary tree, determine if it is a valid binary search tree (BST).
Assume a BST is defined as follows:
Example 1:
2 / 1 3
Binary tree [2,1,3], return true.
Example 2:
1 / 2 3
Binary tree [1,2,3], return false.
分析： 判断中序遍历的是不是逐渐增大的，如果不是，return false, 如果是，return true。
/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: bool isValidBST(TreeNode* root) { if(root==NULL) return true; stack<TreeNode*> s; TreeNode* cur=root; TreeNode* pre=nullptr; while(1){ while(cur){ s.push(cur); cur =cur->left; } if(s.empty()) break; cur = s.top(); s.pop(); if(pre!=nullptr && pre->val >= cur->val) return false; pre = cur; cur = cur->right; } return true; } };
标签：efi arch int div 分析 process sub prot struct
原文地址：http://www.cnblogs.com/willwu/p/6056492.html
