刷题104. Maximum Depth of Binary Tree
一、题目说明
题目104. Maximum Depth of Binary Tree,求二叉树的最大高度。难度是Easy!
二、我的解答
按层遍历二叉树,就可以计算最大深度。下面是非递归算法:
class Solution{
public:
int maxDepth(TreeNode* root){
queue<TreeNode*> q;
TreeNode* p;
if(root==NULL) return 0;
q.push(root);
int maxDep = 0;
int curLevelNum = 1,nextLevelNum = 0;
while(! q.empty()){
for(int i=0;i<curLevelNum;i++){
p = q.front();
q.pop();
if(p->left !=NULL){
q.push(p->left);
nextLevelNum++;
}
if(p->right !=NULL){
q.push(p->right);
nextLevelNum++;
}
}
curLevelNum = nextLevelNum;
nextLevelNum = 0;
maxDep++;
}
return maxDep;
}
};
性能如下:
Runtime: 8 ms, faster than 89.13% of C++ online submissions for Maximum Depth of Binary Tree.
Memory Usage: 19.3 MB, less than 79.12% of C++ online submissions for Maximum Depth of Binary Tree.
三、优化措施
Easy,就不优化了。
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