Description

Submission

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    bool isEvenOddTree(TreeNode* root) {
        queue<TreeNode*> q;
        q.push(root);

        for(int isEven = 1; !q.empty(); isEven = (isEven + 1) % 2) {
            int count = q.size();
            int prev = isEven ? numeric_limits<int>::min() : numeric_limits<int>::max();
            for(int i = 0; i < count; ++i) {
                TreeNode* curNode = q.front();
                q.pop();

                if(isEven) {
                    if(curNode->val % 2 == 0) return false;
                    if(curNode->val <= prev) return false;
                } else {
                    if(curNode->val % 2 == 1) return false;
                    if(curNode->val >= prev) return false;
                }
                
                if(curNode->left) q.push(curNode->left);
                if(curNode->right) q.push(curNode->right);

                prev = curNode->val;
            }
        }
        return true;
    }
};