C 解法, 执行用时: 1ms, 内存消耗: 348KB, 提交时间: 2021-05-11

#include <stdio.h>
#include <stdlib.h>
int main(void)
{
    int num, p, c, h, tmp;
    
    for( ; scanf("%d", &num)!=EOF; ){
        int tree_structure[1008] = {0};
        tree_structure[0] = h = 1;
        for(int i=1; i<num; i++){
            scanf("%d%d", &p, &c);
            if( !(tmp=tree_structure[p]) ){ printf("Another Tree Root Node!!\n");   continue; }

            tree_structure[c] = tmp+1;
            if(tmp == h) h++;
        }
        printf("%d\n", h);
    }
    
    return 0;
}

C++ 解法, 执行用时: 1ms, 内存消耗: 372KB, 提交时间: 2017-10-13

#include<iostream>
using namespace std;
class Node{
    int data;
    Node *leftChild;
    Node *rightChild;
public:
    Node(){leftChild = rightChild = NULL;}
    void setLeft(int d){
        leftChild = new Node();
        leftChild->data = d;
    }
    void setData(int d){
        data = d;
    }
    int getData(){
        return data;
    }
    Node *getLeftChild(){
        return leftChild;
    }
    Node *getRightChild(){
        return rightChild;
    }
     void setRight(int d){
        rightChild = new Node();
        rightChild->data = d;
    }
    inline bool leftEmpty(){
        return leftChild == NULL;
    }
    inline bool rightEmpty(){
        return rightChild == NULL;
    }
};
class Tree{
    Node *root;
    void del(Node *r){
        if(r == NULL)return;
        del(root->getLeftChild());
        del(root->getRightChild());
        delete r;
    }
public:
    Tree(){root = NULL;}
    void connect(const int &p,const int &c){
        if(root == NULL){
            root = new Node();
            root -> setData(p);
            root -> setLeft(c);
        }else{
            preOrder(root,p,c);
        }
    }
    int getHeight(){
        return height(root);
    }
    int height(Node* r){
        if(r == NULL)return 0;
        if(r->leftEmpty() && r->rightEmpty())return 1;
        int left,right;
        left = height(r->getLeftChild());
        right = height(r->getRightChild());
        return (left>right?left:right)+1;
    }
    bool preOrder(Node *r,const int &p,const int &c){
        if(r == NULL)return false;
        if(r->getData() == p){
            if(r->leftEmpty()){
                r->setLeft(c);
            }else if(r->rightEmpty()){
                 r->setRight(c);
            }else return false;
            return true;
        }
        if(preOrder(r->getLeftChild(),p,c))
            return true;
        if(preOrder(r->getRightChild(),p,c))
            return true;
        return false;
    }
    ~Tree(){
        if(root != NULL)
            delete(root);
    }
};

int main(){
    int n;
    int num_parent,num_child;
    Tree tree;
    cin>>n;
    for(int i = 0;i < n-1;++i){
        cin>>num_parent>>num_child;
        tree.connect(num_parent,num_child);
    }
    cout<<tree.getHeight()<<endl;
    
    return 0;
}

C++ 解法, 执行用时: 1ms, 内存消耗: 376KB, 提交时间: 2017-11-04

#include <iostream>
#include <vector>
using namespace std;
int main()
{
    int n,H = 1;
    int i = 0;
    int f,c, h;
    vector<int> nodes(1000, 0);    //有效节点的高度
    nodes[0] = 1; // 题目说了至少有一个节点，高度只是是1
    vector<int> childnum(1000, 0); //记录节点的孩子数量
    cin >> n;
    while(--n){
        cin >> f >> c;
        //父节点不存在 或者 父节点已有两个子节点 就跳过
        if(nodes[f]==0 || childnum[f] == 2)
            continue;
        childnum[f] += 1;
        h = nodes[f] + 1;
        nodes[c] = h;
        if(h > H) H = h;
    }
    cout << H;
    return 0;
}

C++ 解法, 执行用时: 1ms, 内存消耗: 376KB, 提交时间: 2017-10-10

#include<iostream>
#include<vector>
#include<queue>
using namespace std;

int main(){
    int n;
    cin>>n;
    vector<vector<int>> ad(n,{-1});
    queue<int> w;
    int depth=1;
    int temp1,temp2;
    for(int i=0;i<n-1;i++)
    {
      cin>>temp1>>temp2;
      if(ad[temp1].size()<3)
         ad[temp1].push_back(temp2);
    }
    w.push(0);
    w.push(-1);
    while(w.size()!=0)
    {
       temp1=w.front();
        w.pop();
       if(temp1!=-1)
       {
           for(int j=1;j<ad[temp1].size();j++)
                w.push(ad[temp1][j]);
       }
       else 
       {
         if(w.size()!=0)
            {w.push(-1);depth++;}
         else {cout<<depth<<endl;return 0;}
       }
    }
}

C++ 解法, 执行用时: 1ms, 内存消耗: 376KB, 提交时间: 2017-09-30

#include<iostream>
#include<vector>

using namespace std;

vector<int> bt[1000];

int deepFind(int index)
{   
    int len=1;
    if(0==bt[index].size()) return 1;
    for(int i=0;(i<bt[index].size())&&(i<2);i++)
        len=max(len,deepFind(bt[index][i]));
    return len+1;
}

int main(int argc,char* argv[])
{
    int n,k1,k2;
    cin>>n;
    while(n)
    {
        cin>>k1>>k2;
        bt[k1].push_back(k2);
        n--;
    }
    cout<<deepFind(0)<<endl;
}