1021. Deepest Root (25)

本文介绍了一种算法,用于在给定的连通无环图(即树)中找到能够生成最高树的根节点,并提供了相应的C++实现代码。若图不是一棵树,则输出错误信息并给出连通组件的数量。

摘要生成于 C知道 ,由 DeepSeek-R1 满血版支持, 前往体验 >

A graph which is connected and acyclic can be considered a tree. The height of the tree depends on the selected root. Now you are supposed to find the root that results in a highest tree. Such a root is called the deepest root.

Input Specification:

Each input file contains one test case. For each case, the first line contains a positive integer N (<=10000) which is the number of nodes, and hence the nodes are numbered from 1 to N. Then N-1 lines follow, each describes an edge by given the two adjacent nodes’ numbers.

Output Specification:

For each test case, print each of the deepest roots in a line. If such a root is not unique, print them in increasing order of their numbers. In case that the given graph is not a tree, print “Error: K components” where K is the number of connected components in the graph.
Sample Input 1:

5
1 2
1 3
1 4
2 5

Sample Output 1:

3
4
5

Sample Input 2:

5
1 3
1 4
2 5
3 4

Sample Output 2:

Error: 2 components

#include<iostream>
#include<vector>
#include<algorithm>
#include<string.h>
using namespace std;
vector<int> node[10010];
bool visited[10010];
vector<int> out;
void init(){
    memset(visited,false,10010);
}
int maxdeep=0;
void dfs(int k,int deep,int &tmax){
    if(!visited[k]){
        if(tmax<deep) 
            tmax=deep;
        visited[k]=true;
        for(int i=0;i<node[k].size();i++){
           dfs(node[k][i],deep+1,tmax);
        }
    }
}
int main(){
    freopen("in.txt","r",stdin);
    int n,c1,c2,components=0;
    scanf("%d",&n);
    for(int i=1;i<n;i++){
        scanf("%d%d",&c1,&c2);
        node[c1].push_back(c2);
        node[c2].push_back(c1);
    }
    for(int i=1;i<=n;i++)
    {
        int t=0;
        if(!visited[i]){
            components++;
            dfs(i,1,t);
        }
    }
    if(components==1){
    for(int i=1;i<=n;i++){
        init();
        int tmax=0;
        dfs(i,1,tmax);
        if(tmax>maxdeep){
            maxdeep=tmax;
            out.clear();
            out.push_back(i);
        }
        else if(tmax==maxdeep){
            out.push_back(i);
        }
    }
    sort(out.begin(),out.end());
    for(int i=0;i<out.size();i++){
        printf("%d\n",out[i]);
    }
    }
    else printf("Error: %d components",components);
    return 0;
}
# -*- coding: utf-8 -*- '''请在Begin-End之间补充代码, 完成BinaryTree类''' class BinaryTree: # 创建左右子树为空的根结点 def __init__(self, rootObj): self.key = rootObj # 成员key保存根结点数据项 self.leftChild = None # 成员leftChild初始化为空 self.rightChild = None # 成员rightChild初始化为空 # 把newNode插入到根的左子树 def insertLeft(self, newNode): if self.leftChild is None: self.leftChild = BinaryTree(newNode) # 左子树指向由newNode所生成的BinaryTree else: t = BinaryTree(newNode) # 创建一个BinaryTree类型的新结点t t.leftChild = self.leftChild # 新结点的左子树指向原来根的左子树 self.leftChild = t # 根结点的左子树指向结点t # 把newNode插入到根的右子树 def insertRight(self, newNode): if self.rightChild is None: # 右子树指向由newNode所生成的BinaryTree # ********** Begin ********** # self.rightChild = BinaryTree(newNode) # ********** End ********** # else: t = BinaryTree(newNode) t.rightChild = self.rightChild self.rightChild = t # ********** End ********** # # 取得右子树,返回值是一个BinaryTree类型的对象 def getRightChild(self): # ********** Begin ********** # return self.rightChild # ********** End ********** # # 取得左子树 def getLeftChild(self): # ********** Begin ********** # return self.leftChild # ********** End ********** # # 设置根结点的值 def setRootVal(self, obj): # 将根结点的值赋值为obj # ********** Begin ********** # self.key = obj # ********** End ********** # # 取得根结点的值 def getRootVal(self): # ********** Begin ********** # return self.key # ********** End ********** # # 主程序 input_str = input() nodes = input_str.split(',') # 创建根节点 root = BinaryTree(nodes[0]) # 插入左子树和右子树 if len(nodes) > 1: root.insertLeft(nodes[1]) if len(nodes) > 2: root.insertRight(nodes[2]) # 前三行输出:对创建的二叉树按编号顺序输出结点 print(root.getRootVal()) left_child = root.getLeftChild
最新发布
03-18
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值