有一棵二叉树,请设计一个算法,按照层次打印这棵二叉树。
给定二叉树的根结点root,请返回打印结果,结果按照每一层一个数组进行储存,所有数组的顺序按照层数从上往下,且每一层的数组内元素按照从左往右排列。保证结点数小于等于500。
https://blog.csdn.net/qq_38068435/article/details/79662624
/*
struct TreeNode {
int val;
struct TreeNode *left;
struct TreeNode *right;
TreeNode(int x) :
val(x), left(NULL), right(NULL) {
}
};*/
class TreePrinter {
public:
vector<vector<int> > printTree(TreeNode* root) {
vector<vector<int>> v;
if(root==NULL)
return v;
queue<TreeNode*> Q;
Q.push(root);
while(!Q.empty()){
int size = Q.size();
vector<int>row;
for (int i = 0; i < size; i++){
TreeNode* cur = Q.front();
Q.pop();
row.push_back(cur->val);
if (cur->left)Q.push(cur->left);
if (cur->right)Q.push(cur->right);
}
v.push_back(row);
}
return v;
}
};