标签：leetcode   算法   

问题描述：

Two elements of a binary search tree (BST) are swapped by mistake.

Recover the tree without changing its structure.

代码：

void recoverTree(TreeNode *root) {
        if(root ==NULL)
            return;
        
        bool haveOne = false;
        bool isFirst = true;
        
        TreeNode *pre = root;
        TreeNode* p = root;
        vector<TreeNode*> melement(2);
        stack<TreeNode* > myStack;
        
        while(p!=NULL || !myStack.empty())
        {
            while(p!=NULL){
                myStack.push(p);
                p = p->left;
            }
            
            p = myStack.top();
            if(isFirst){
                isFirst = false;
                pre = p;
            }
            else {
                if(p->val < pre->val){
                    if(!haveOne){
                        melement[0] = pre;
                        melement[1] = p;
                        haveOne = true;   
                    }
                    else{
                        melement[1] = p;
                        break;
                    }
                }
                pre = p;
            }
            myStack.pop();
            p = p->right;
            
        }
        int temp = melement[0]->val;
        melement[0]->val = melement[1]->val;
        melement[1]->val = temp;
        return;
        
    }

[leetcode]99 Recover Binary Search Tree

标签：leetcode   算法   

原文地址：http://blog.csdn.net/chenlei0630/article/details/42746615