题目描述
输入一棵二叉树,求该树的深度。从根结点到叶结点依次经过的结点(含根、叶结点)形成树的一条路径,最长路径的长度为树的深度。
思路
思路一: 递归计算节点左右儿子最大距离
Code
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn=1e5+7;
struct TreeNode {
int val;
struct TreeNode *left;
struct TreeNode *right;
TreeNode(int x=0) :
val(x), left(NULL), right(NULL) {
}
};
int TreeDepth(TreeNode* pRoot){
if(pRoot!=NULL)return max(TreeDepth(pRoot->left),TreeDepth(pRoot->right))+1;
return 0;
}
void dfs(TreeNode* pRoot){ //建树
scanf("%d",&pRoot->val);
int flag;
scanf("%d",&flag);
if(flag==-1){
TreeNode *left=new TreeNode;
pRoot->left=left;
dfs(pRoot->left);
}
else if(flag==-2){
TreeNode *left=new TreeNode;
pRoot->right=left;
dfs(pRoot->right);
}
else if(flag==-3){
TreeNode *left=new TreeNode;
TreeNode *right=new TreeNode;
pRoot->right=right;
pRoot->left=left;
dfs(pRoot->left);
dfs(pRoot->right);
}
else if(flag==-4)return;
}
int main(){
TreeNode root;
int x;
dfs(&root);
cout<<TreeDepth(&root)<<endl;
return 0;
}
思路二: 栈模拟递归
思路一: 利用队列进行BFS,计算节点深度