1021. Deepest Root (25)

来源：互联网发布：控制台运行java程序编辑：程序博客网时间：2024/05/01 05:49

开始用各个叶节点dfs遍历，找最大deep，运行超时，然后评论里发现个方法，挺赞
https://www.nowcoder.com/questionTerminal/f793ad2e0c7344efa8b6c18d10d4b67b

#include<iostream>#include<algorithm>#include<vector>#define MAX_V 10002using namespace std;vector<int> arc[MAX_V];//相等于邻接矩阵vector<int> P;//输出的数组int dis[MAX_V];//相对于root距离int N,dis_max=0;//相对于root最大距离bool visited[MAX_V] = {0};void dfs(int index){    if (dis_max < dis[index]) dis_max = dis[index];    for (auto x : arc[index])    {        if (visited[x] == NULL)        {            dis[x] = dis[index] + 1;            visited[x] = true;            dfs(x);        }    }}int main(){    cin >> N;    for (int t = 1;t < N;t++)    {        int i, j;        cin >> i >> j;        arc[i].push_back(j);        arc[j].push_back(i);    }    int count=0;    for (int t = 1;t <= N;t++)    {        if (visited[t] == false)        {            dis[t] = 0;            visited[t] = true;            dfs(t);            count++;        }    }    if (count != 1) cout << "Error: " << count << " components" << endl;    else    {        for (int t = 1;t <= N;t++)        {            if (dis[t] == dis_max) P.push_back(t);            visited[t] = false;        }        visited[P.back()] = true;        dfs(P.back());        for (int t = 1;t <= N;t++)        {            if (find(P.begin(), P.end(), t) == P.end())                if (dis[t] == dis_max) P.push_back(t);        }        sort(P.begin(), P.end());        for (auto x : P)            cout << x << endl;    }}

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