剑指offer（56）-按之字形顺序打印二叉树

题目描述

代码

/*
struct TreeNode {
int val;
struct TreeNode *left;
struct TreeNode *right;
TreeNode(int x) :
val(x), left(NULL), right(NULL) {
}
};
*/
class Solution {
public:
vector<vector<int> > Print(TreeNode* pRoot) {

vector<vector<int>> result;
stack<TreeNode*> stack1,stack2;
bool direction = true;
if (pRoot != NULL) {
stack1.push(pRoot);
}
struct TreeNode *node;
while (!stack1.empty() || !stack2.empty()) {
vector<int> data;
if (!stack1.empty()) {
while (!stack1.empty()) {
node = stack1.top();
stack1.pop();
data.push_back(node->val);
if (node->left != NULL) {
stack2.push(node->left);
}
if (node->right != NULL) {
stack2.push(node->right);
}
}
result.push_back(data);
}else if (!stack2.empty()){
while (!stack2.empty()) {
node = stack2.top();
stack2.pop();
data.push_back(node->val);
if (node->right != NULL) {
stack1.push(node->right);
}
if (node->left != NULL) {
stack1.push(node->left);
}
}
result.push_back(data);
}
}
return result;

}

};